diff --git a/libs/dumputils/dump_utils.cpp b/libs/dumputils/dump_utils.cpp
index 40f6b43..8e762f1 100644
--- a/libs/dumputils/dump_utils.cpp
+++ b/libs/dumputils/dump_utils.cpp
@@ -46,6 +46,7 @@
 static const char* hal_interfaces_to_dump[] {
         "android.hardware.audio@2.0::IDevicesFactory",
         "android.hardware.audio@4.0::IDevicesFactory",
+        "android.hardware.biometrics.face@1.0::IBiometricsFace",
         "android.hardware.bluetooth@1.0::IBluetoothHci",
         "android.hardware.camera.provider@2.4::ICameraProvider",
         "android.hardware.drm@1.0::IDrmFactory",
diff --git a/libs/graphicsenv/GraphicsEnv.cpp b/libs/graphicsenv/GraphicsEnv.cpp
index 24b6c2d..4a39069 100644
--- a/libs/graphicsenv/GraphicsEnv.cpp
+++ b/libs/graphicsenv/GraphicsEnv.cpp
@@ -213,7 +213,8 @@
         case GraphicsEnv::Driver::GL:
         case GraphicsEnv::Driver::GL_UPDATED:
         case GraphicsEnv::Driver::ANGLE: {
-            if (mGpuStats.glDriverToLoad == GraphicsEnv::Driver::NONE) {
+            if (mGpuStats.glDriverToLoad == GraphicsEnv::Driver::NONE ||
+                mGpuStats.glDriverToLoad == GraphicsEnv::Driver::GL) {
                 mGpuStats.glDriverToLoad = driver;
                 break;
             }
@@ -225,7 +226,8 @@
         }
         case Driver::VULKAN:
         case Driver::VULKAN_UPDATED: {
-            if (mGpuStats.vkDriverToLoad == GraphicsEnv::Driver::NONE) {
+            if (mGpuStats.vkDriverToLoad == GraphicsEnv::Driver::NONE ||
+                mGpuStats.vkDriverToLoad == GraphicsEnv::Driver::VULKAN) {
                 mGpuStats.vkDriverToLoad = driver;
                 break;
             }
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 34575f5..e3e63ee 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -34,6 +34,7 @@
         "BufferItemConsumer.cpp",
         "ConsumerBase.cpp",
         "CpuConsumer.cpp",
+        "DebugEGLImageTracker.cpp",
         "DisplayEventReceiver.cpp",
         "GLConsumer.cpp",
         "GuiConfig.cpp",
diff --git a/libs/gui/BufferQueueProducer.cpp b/libs/gui/BufferQueueProducer.cpp
index 9c311a3..92ab410 100644
--- a/libs/gui/BufferQueueProducer.cpp
+++ b/libs/gui/BufferQueueProducer.cpp
@@ -936,6 +936,15 @@
                     }
                 }
 
+                // Make sure to merge the damage rect from the frame we're about
+                // to drop into the new frame's damage rect.
+                if (last.mSurfaceDamage.bounds() == Rect::INVALID_RECT ||
+                    item.mSurfaceDamage.bounds() == Rect::INVALID_RECT) {
+                    item.mSurfaceDamage = Region::INVALID_REGION;
+                } else {
+                    item.mSurfaceDamage |= last.mSurfaceDamage;
+                }
+
                 // Overwrite the droppable buffer with the incoming one
                 mCore->mQueue.editItemAt(mCore->mQueue.size() - 1) = item;
                 frameReplacedListener = mCore->mConsumerListener;
diff --git a/libs/gui/DebugEGLImageTracker.cpp b/libs/gui/DebugEGLImageTracker.cpp
new file mode 100644
index 0000000..ab6f364
--- /dev/null
+++ b/libs/gui/DebugEGLImageTracker.cpp
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android-base/stringprintf.h>
+#include <cutils/properties.h>
+#include <gui/DebugEGLImageTracker.h>
+
+#include <cinttypes>
+#include <unordered_map>
+
+using android::base::StringAppendF;
+
+std::mutex DebugEGLImageTracker::mInstanceLock;
+std::atomic<DebugEGLImageTracker *> DebugEGLImageTracker::mInstance;
+
+class DebugEGLImageTrackerNoOp : public DebugEGLImageTracker {
+public:
+    DebugEGLImageTrackerNoOp() = default;
+    ~DebugEGLImageTrackerNoOp() override = default;
+    void create(const char * /*from*/) override {}
+    void destroy(const char * /*from*/) override {}
+
+    void dump(std::string & /*result*/) override {}
+};
+
+class DebugEGLImageTrackerImpl : public DebugEGLImageTracker {
+public:
+    DebugEGLImageTrackerImpl() = default;
+    ~DebugEGLImageTrackerImpl() override = default;
+    void create(const char * /*from*/) override;
+    void destroy(const char * /*from*/) override;
+
+    void dump(std::string & /*result*/) override;
+
+private:
+    std::mutex mLock;
+    std::unordered_map<std::string, int64_t> mCreateTracker;
+    std::unordered_map<std::string, int64_t> mDestroyTracker;
+
+    int64_t mTotalCreated = 0;
+    int64_t mTotalDestroyed = 0;
+};
+
+DebugEGLImageTracker *DebugEGLImageTracker::getInstance() {
+    std::lock_guard lock(mInstanceLock);
+    if (mInstance == nullptr) {
+        char value[PROPERTY_VALUE_MAX];
+        property_get("debug.sf.enable_egl_image_tracker", value, "0");
+        const bool enabled = static_cast<bool>(atoi(value));
+
+        if (enabled) {
+            mInstance = new DebugEGLImageTrackerImpl();
+        } else {
+            mInstance = new DebugEGLImageTrackerNoOp();
+        }
+    }
+
+    return mInstance;
+}
+
+void DebugEGLImageTrackerImpl::create(const char *from) {
+    std::lock_guard lock(mLock);
+    mCreateTracker[from]++;
+    mTotalCreated++;
+}
+
+void DebugEGLImageTrackerImpl::destroy(const char *from) {
+    std::lock_guard lock(mLock);
+    mDestroyTracker[from]++;
+    mTotalDestroyed++;
+}
+
+void DebugEGLImageTrackerImpl::dump(std::string &result) {
+    std::lock_guard lock(mLock);
+    StringAppendF(&result, "Live EGL Image objects: %" PRIi64 "\n",
+                  mTotalCreated - mTotalDestroyed);
+    StringAppendF(&result, "Total EGL Image created: %" PRIi64 "\n", mTotalCreated);
+    for (const auto &[from, count] : mCreateTracker) {
+        StringAppendF(&result, "\t%s: %" PRIi64 "\n", from.c_str(), count);
+    }
+    StringAppendF(&result, "Total EGL Image destroyed: %" PRIi64 "\n", mTotalDestroyed);
+    for (const auto &[from, count] : mDestroyTracker) {
+        StringAppendF(&result, "\t%s: %" PRIi64 "\n", from.c_str(), count);
+    }
+}
diff --git a/libs/gui/DisplayEventReceiver.cpp b/libs/gui/DisplayEventReceiver.cpp
index f5cf1c4..b8faa2d 100644
--- a/libs/gui/DisplayEventReceiver.cpp
+++ b/libs/gui/DisplayEventReceiver.cpp
@@ -32,10 +32,11 @@
 
 // ---------------------------------------------------------------------------
 
-DisplayEventReceiver::DisplayEventReceiver(ISurfaceComposer::VsyncSource vsyncSource) {
+DisplayEventReceiver::DisplayEventReceiver(ISurfaceComposer::VsyncSource vsyncSource,
+                                           ISurfaceComposer::ConfigChanged configChanged) {
     sp<ISurfaceComposer> sf(ComposerService::getComposerService());
     if (sf != nullptr) {
-        mEventConnection = sf->createDisplayEventConnection(vsyncSource);
+        mEventConnection = sf->createDisplayEventConnection(vsyncSource, configChanged);
         if (mEventConnection != nullptr) {
             mDataChannel = std::make_unique<gui::BitTube>();
             mEventConnection->stealReceiveChannel(mDataChannel.get());
diff --git a/libs/gui/GLConsumer.cpp b/libs/gui/GLConsumer.cpp
index 8d66154..8199c98 100644
--- a/libs/gui/GLConsumer.cpp
+++ b/libs/gui/GLConsumer.cpp
@@ -34,6 +34,7 @@
 #include <math/mat4.h>
 
 #include <gui/BufferItem.h>
+#include <gui/DebugEGLImageTracker.h>
 #include <gui/GLConsumer.h>
 #include <gui/ISurfaceComposer.h>
 #include <gui/SurfaceComposerClient.h>
@@ -944,6 +945,7 @@
         if (!eglDestroyImageKHR(mEglDisplay, mEglImage)) {
            ALOGE("~EglImage: eglDestroyImageKHR failed");
         }
+        DEBUG_EGL_IMAGE_TRACKER_DESTROY();
         eglTerminate(mEglDisplay);
     }
 }
@@ -957,6 +959,7 @@
         if (!eglDestroyImageKHR(mEglDisplay, mEglImage)) {
            ALOGE("createIfNeeded: eglDestroyImageKHR failed");
         }
+        DEBUG_EGL_IMAGE_TRACKER_DESTROY();
         eglTerminate(mEglDisplay);
         mEglImage = EGL_NO_IMAGE_KHR;
         mEglDisplay = EGL_NO_DISPLAY;
@@ -1006,7 +1009,10 @@
         EGLint error = eglGetError();
         ALOGE("error creating EGLImage: %#x", error);
         eglTerminate(dpy);
+    } else {
+        DEBUG_EGL_IMAGE_TRACKER_CREATE();
     }
+
     return image;
 }
 
diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 9590df7..12deaf0 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -278,8 +278,8 @@
         return NO_ERROR;
     }
 
-    virtual sp<IDisplayEventConnection> createDisplayEventConnection(VsyncSource vsyncSource)
-    {
+    virtual sp<IDisplayEventConnection> createDisplayEventConnection(VsyncSource vsyncSource,
+                                                                     ConfigChanged configChanged) {
         Parcel data, reply;
         sp<IDisplayEventConnection> result;
         int err = data.writeInterfaceToken(
@@ -288,6 +288,7 @@
             return result;
         }
         data.writeInt32(static_cast<int32_t>(vsyncSource));
+        data.writeInt32(static_cast<int32_t>(configChanged));
         err = remote()->transact(
                 BnSurfaceComposer::CREATE_DISPLAY_EVENT_CONNECTION,
                 data, &reply);
@@ -1155,8 +1156,11 @@
         }
         case CREATE_DISPLAY_EVENT_CONNECTION: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
-            sp<IDisplayEventConnection> connection(createDisplayEventConnection(
-                    static_cast<ISurfaceComposer::VsyncSource>(data.readInt32())));
+            auto vsyncSource = static_cast<ISurfaceComposer::VsyncSource>(data.readInt32());
+            auto configChanged = static_cast<ISurfaceComposer::ConfigChanged>(data.readInt32());
+
+            sp<IDisplayEventConnection> connection(
+                    createDisplayEventConnection(vsyncSource, configChanged));
             reply->writeStrongBinder(IInterface::asBinder(connection));
             return NO_ERROR;
         }
diff --git a/libs/gui/Surface.cpp b/libs/gui/Surface.cpp
index e6eb327..9fe5de8 100644
--- a/libs/gui/Surface.cpp
+++ b/libs/gui/Surface.cpp
@@ -1920,7 +1920,8 @@
     return OK;
 }
 
-status_t Surface::attachAndQueueBuffer(Surface* surface, sp<GraphicBuffer> buffer) {
+status_t Surface::attachAndQueueBufferWithDataspace(Surface* surface, sp<GraphicBuffer> buffer,
+                                                    Dataspace dataspace) {
     if (buffer == nullptr) {
         return BAD_VALUE;
     }
@@ -1929,6 +1930,11 @@
     if (err != OK) {
         return err;
     }
+    ui::Dataspace tmpDataspace = surface->getBuffersDataSpace();
+    err = surface->setBuffersDataSpace(dataspace);
+    if (err != OK) {
+        return err;
+    }
     err = surface->attachBuffer(buffer->getNativeBuffer());
     if (err != OK) {
         return err;
@@ -1937,6 +1943,10 @@
     if (err != OK) {
         return err;
     }
+    err = surface->setBuffersDataSpace(tmpDataspace);
+    if (err != OK) {
+        return err;
+    }
     err = surface->disconnect(NATIVE_WINDOW_API_CPU);
     return err;
 }
diff --git a/libs/gui/include/gui/DebugEGLImageTracker.h b/libs/gui/include/gui/DebugEGLImageTracker.h
new file mode 100644
index 0000000..5d369c9
--- /dev/null
+++ b/libs/gui/include/gui/DebugEGLImageTracker.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <atomic>
+#include <mutex>
+#include <string>
+
+class DebugEGLImageTracker {
+public:
+    static DebugEGLImageTracker *getInstance();
+
+    virtual void create(const char *from) = 0;
+    virtual void destroy(const char *from) = 0;
+
+    virtual void dump(std::string &result) = 0;
+
+protected:
+    DebugEGLImageTracker() = default;
+    virtual ~DebugEGLImageTracker() = default;
+    DebugEGLImageTracker(const DebugEGLImageTracker &) = delete;
+
+    static std::mutex mInstanceLock;
+    static std::atomic<DebugEGLImageTracker *> mInstance;
+};
+
+#define DEBUG_EGL_IMAGE_TRACKER_CREATE() \
+    (DebugEGLImageTracker::getInstance()->create(__PRETTY_FUNCTION__))
+#define DEBUG_EGL_IMAGE_TRACKER_DESTROY() \
+    (DebugEGLImageTracker::getInstance()->destroy(__PRETTY_FUNCTION__))
\ No newline at end of file
diff --git a/libs/gui/include/gui/DisplayEventReceiver.h b/libs/gui/include/gui/DisplayEventReceiver.h
index 22de751..a558cf9 100644
--- a/libs/gui/include/gui/DisplayEventReceiver.h
+++ b/libs/gui/include/gui/DisplayEventReceiver.h
@@ -88,10 +88,13 @@
      * DisplayEventReceiver creates and registers an event connection with
      * SurfaceFlinger. VSync events are disabled by default. Call setVSyncRate
      * or requestNextVsync to receive them.
+     * To receive Config Changed events specify this in the constructor.
      * Other events start being delivered immediately.
      */
     explicit DisplayEventReceiver(
-            ISurfaceComposer::VsyncSource vsyncSource = ISurfaceComposer::eVsyncSourceApp);
+            ISurfaceComposer::VsyncSource vsyncSource = ISurfaceComposer::eVsyncSourceApp,
+            ISurfaceComposer::ConfigChanged configChanged =
+                    ISurfaceComposer::eConfigChangedSuppress);
 
     /*
      * ~DisplayEventReceiver severs the connection with SurfaceFlinger, new events
diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index e2f7736..c84910b 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -90,6 +90,8 @@
         eVsyncSourceSurfaceFlinger = 1
     };
 
+    enum ConfigChanged { eConfigChangedSuppress = 0, eConfigChangedDispatch = 1 };
+
     /*
      * Create a connection with SurfaceFlinger.
      */
@@ -97,7 +99,8 @@
 
     /* return an IDisplayEventConnection */
     virtual sp<IDisplayEventConnection> createDisplayEventConnection(
-            VsyncSource vsyncSource = eVsyncSourceApp) = 0;
+            VsyncSource vsyncSource = eVsyncSourceApp,
+            ConfigChanged configChanged = eConfigChangedSuppress) = 0;
 
     /* create a virtual display
      * requires ACCESS_SURFACE_FLINGER permission.
diff --git a/libs/gui/include/gui/Surface.h b/libs/gui/include/gui/Surface.h
index 0c471bb..5c6a1ee 100644
--- a/libs/gui/include/gui/Surface.h
+++ b/libs/gui/include/gui/Surface.h
@@ -292,7 +292,8 @@
 
     ui::Dataspace getBuffersDataSpace();
 
-    static status_t attachAndQueueBuffer(Surface* surface, sp<GraphicBuffer> buffer);
+    static status_t attachAndQueueBufferWithDataspace(Surface* surface, sp<GraphicBuffer> buffer,
+                                                      ui::Dataspace dataspace);
 
 protected:
     enum { NUM_BUFFER_SLOTS = BufferQueueDefs::NUM_BUFFER_SLOTS };
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 960cf18..d370858 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -548,8 +548,8 @@
     }
 
     sp<ISurfaceComposerClient> createConnection() override { return nullptr; }
-    sp<IDisplayEventConnection> createDisplayEventConnection(ISurfaceComposer::VsyncSource)
-            override {
+    sp<IDisplayEventConnection> createDisplayEventConnection(
+            ISurfaceComposer::VsyncSource, ISurfaceComposer::ConfigChanged) override {
         return nullptr;
     }
     sp<IBinder> createDisplay(const String8& /*displayName*/,
diff --git a/libs/renderengine/Android.bp b/libs/renderengine/Android.bp
index 36211ca..cc252d6 100644
--- a/libs/renderengine/Android.bp
+++ b/libs/renderengine/Android.bp
@@ -26,6 +26,7 @@
         "libgui",
         "liblog",
         "libnativewindow",
+        "libprocessgroup",
         "libsync",
         "libui",
         "libutils",
@@ -51,6 +52,7 @@
         "gl/GLExtensions.cpp",
         "gl/GLFramebuffer.cpp",
         "gl/GLImage.cpp",
+        "gl/ImageManager.cpp",
         "gl/Program.cpp",
         "gl/ProgramCache.cpp",
     ],
diff --git a/libs/renderengine/gl/GLESRenderEngine.cpp b/libs/renderengine/gl/GLESRenderEngine.cpp
index 46a8e9e..d2a7525 100644
--- a/libs/renderengine/gl/GLESRenderEngine.cpp
+++ b/libs/renderengine/gl/GLESRenderEngine.cpp
@@ -19,9 +19,8 @@
 #define LOG_TAG "RenderEngine"
 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
 
-#include "GLESRenderEngine.h"
-
-#include <math.h>
+#include <sched.h>
+#include <cmath>
 #include <fstream>
 #include <sstream>
 #include <unordered_set>
@@ -31,6 +30,7 @@
 #include <android-base/stringprintf.h>
 #include <cutils/compiler.h>
 #include <cutils/properties.h>
+#include <gui/DebugEGLImageTracker.h>
 #include <renderengine/Mesh.h>
 #include <renderengine/Texture.h>
 #include <renderengine/private/Description.h>
@@ -42,6 +42,7 @@
 #include <ui/Region.h>
 #include <utils/KeyedVector.h>
 #include <utils/Trace.h>
+#include "GLESRenderEngine.h"
 #include "GLExtensions.h"
 #include "GLFramebuffer.h"
 #include "GLImage.h"
@@ -422,10 +423,13 @@
         mTraceGpuCompletion = true;
         mFlushTracer = std::make_unique<FlushTracer>(this);
     }
+    mImageManager = std::make_unique<ImageManager>(this);
     mDrawingBuffer = createFramebuffer();
 }
 
 GLESRenderEngine::~GLESRenderEngine() {
+    // Destroy the image manager first.
+    mImageManager = nullptr;
     std::lock_guard<std::mutex> lock(mRenderingMutex);
     unbindFrameBuffer(mDrawingBuffer.get());
     mDrawingBuffer = nullptr;
@@ -433,6 +437,7 @@
         EGLImageKHR expired = mFramebufferImageCache.front().second;
         mFramebufferImageCache.pop_front();
         eglDestroyImageKHR(mEGLDisplay, expired);
+        DEBUG_EGL_IMAGE_TRACKER_DESTROY();
     }
     mImageCache.clear();
     eglMakeCurrent(mEGLDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
@@ -614,64 +619,51 @@
     }
 }
 
-status_t GLESRenderEngine::cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) {
-    std::lock_guard<std::mutex> lock(mRenderingMutex);
-    return cacheExternalTextureBufferLocked(buffer);
-}
-
 status_t GLESRenderEngine::bindExternalTextureBuffer(uint32_t texName,
                                                      const sp<GraphicBuffer>& buffer,
                                                      const sp<Fence>& bufferFence) {
-    std::lock_guard<std::mutex> lock(mRenderingMutex);
-    return bindExternalTextureBufferLocked(texName, buffer, bufferFence);
-}
-
-status_t GLESRenderEngine::cacheExternalTextureBufferLocked(const sp<GraphicBuffer>& buffer) {
     if (buffer == nullptr) {
         return BAD_VALUE;
     }
 
     ATRACE_CALL();
 
-    if (mImageCache.count(buffer->getId()) > 0) {
-        return NO_ERROR;
+    bool found = false;
+    {
+        std::lock_guard<std::mutex> lock(mRenderingMutex);
+        auto cachedImage = mImageCache.find(buffer->getId());
+        found = (cachedImage != mImageCache.end());
     }
 
-    std::unique_ptr<Image> newImage = createImage();
-
-    bool created = newImage->setNativeWindowBuffer(buffer->getNativeBuffer(),
-                                                   buffer->getUsage() & GRALLOC_USAGE_PROTECTED);
-    if (!created) {
-        ALOGE("Failed to create image. size=%ux%u st=%u usage=%#" PRIx64 " fmt=%d",
-              buffer->getWidth(), buffer->getHeight(), buffer->getStride(), buffer->getUsage(),
-              buffer->getPixelFormat());
-        return NO_INIT;
-    }
-    mImageCache.insert(std::make_pair(buffer->getId(), std::move(newImage)));
-
-    return NO_ERROR;
-}
-
-status_t GLESRenderEngine::bindExternalTextureBufferLocked(uint32_t texName,
-                                                           const sp<GraphicBuffer>& buffer,
-                                                           const sp<Fence>& bufferFence) {
-    ATRACE_CALL();
-    status_t cacheResult = cacheExternalTextureBufferLocked(buffer);
-
-    if (cacheResult != NO_ERROR) {
-        return cacheResult;
+    // If we couldn't find the image in the cache at this time, then either
+    // SurfaceFlinger messed up registering the buffer ahead of time or we got
+    // backed up creating other EGLImages.
+    if (!found) {
+        status_t cacheResult = mImageManager->cache(buffer);
+        if (cacheResult != NO_ERROR) {
+            return cacheResult;
+        }
     }
 
-    auto cachedImage = mImageCache.find(buffer->getId());
+    // Whether or not we needed to cache, re-check mImageCache to make sure that
+    // there's an EGLImage. The current threading model guarantees that we don't
+    // destroy a cached image until it's really not needed anymore (i.e. this
+    // function should not be called), so the only possibility is that something
+    // terrible went wrong and we should just bind something and move on.
+    {
+        std::lock_guard<std::mutex> lock(mRenderingMutex);
+        auto cachedImage = mImageCache.find(buffer->getId());
 
-    if (cachedImage == mImageCache.end()) {
-        // We failed creating the image if we got here, so bail out.
-        bindExternalTextureImage(texName, *createImage());
-        return NO_INIT;
+        if (cachedImage == mImageCache.end()) {
+            // We failed creating the image if we got here, so bail out.
+            ALOGE("Failed to create an EGLImage when rendering");
+            bindExternalTextureImage(texName, *createImage());
+            return NO_INIT;
+        }
+
+        bindExternalTextureImage(texName, *cachedImage->second);
     }
 
-    bindExternalTextureImage(texName, *cachedImage->second);
-
     // Wait for the new buffer to be ready.
     if (bufferFence != nullptr && bufferFence->isValid()) {
         if (GLExtensions::getInstance().hasWaitSync()) {
@@ -696,13 +688,81 @@
     return NO_ERROR;
 }
 
+void GLESRenderEngine::cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) {
+    mImageManager->cacheAsync(buffer, nullptr);
+}
+
+std::shared_ptr<ImageManager::Barrier> GLESRenderEngine::cacheExternalTextureBufferForTesting(
+        const sp<GraphicBuffer>& buffer) {
+    auto barrier = std::make_shared<ImageManager::Barrier>();
+    mImageManager->cacheAsync(buffer, barrier);
+    return barrier;
+}
+
+status_t GLESRenderEngine::cacheExternalTextureBufferInternal(const sp<GraphicBuffer>& buffer) {
+    if (buffer == nullptr) {
+        return BAD_VALUE;
+    }
+
+    {
+        std::lock_guard<std::mutex> lock(mRenderingMutex);
+        if (mImageCache.count(buffer->getId()) > 0) {
+            // If there's already an image then fail fast here.
+            return NO_ERROR;
+        }
+    }
+    ATRACE_CALL();
+
+    // Create the image without holding a lock so that we don't block anything.
+    std::unique_ptr<Image> newImage = createImage();
+
+    bool created = newImage->setNativeWindowBuffer(buffer->getNativeBuffer(),
+                                                   buffer->getUsage() & GRALLOC_USAGE_PROTECTED);
+    if (!created) {
+        ALOGE("Failed to create image. size=%ux%u st=%u usage=%#" PRIx64 " fmt=%d",
+              buffer->getWidth(), buffer->getHeight(), buffer->getStride(), buffer->getUsage(),
+              buffer->getPixelFormat());
+        return NO_INIT;
+    }
+
+    {
+        std::lock_guard<std::mutex> lock(mRenderingMutex);
+        if (mImageCache.count(buffer->getId()) > 0) {
+            // In theory it's possible for another thread to recache the image,
+            // so bail out if another thread won.
+            return NO_ERROR;
+        }
+        mImageCache.insert(std::make_pair(buffer->getId(), std::move(newImage)));
+    }
+
+    return NO_ERROR;
+}
+
 void GLESRenderEngine::unbindExternalTextureBuffer(uint64_t bufferId) {
-    std::lock_guard<std::mutex> lock(mRenderingMutex);
-    const auto& cachedImage = mImageCache.find(bufferId);
-    if (cachedImage != mImageCache.end()) {
-        ALOGV("Destroying image for buffer: %" PRIu64, bufferId);
-        mImageCache.erase(bufferId);
-        return;
+    mImageManager->releaseAsync(bufferId, nullptr);
+}
+
+std::shared_ptr<ImageManager::Barrier> GLESRenderEngine::unbindExternalTextureBufferForTesting(
+        uint64_t bufferId) {
+    auto barrier = std::make_shared<ImageManager::Barrier>();
+    mImageManager->releaseAsync(bufferId, barrier);
+    return barrier;
+}
+
+void GLESRenderEngine::unbindExternalTextureBufferInternal(uint64_t bufferId) {
+    std::unique_ptr<Image> image;
+    {
+        std::lock_guard<std::mutex> lock(mRenderingMutex);
+        const auto& cachedImage = mImageCache.find(bufferId);
+
+        if (cachedImage != mImageCache.end()) {
+            ALOGV("Destroying image for buffer: %" PRIu64, bufferId);
+            // Move the buffer out of cache first, so that we can destroy
+            // without holding the cache's lock.
+            image = std::move(cachedImage->second);
+            mImageCache.erase(bufferId);
+            return;
+        }
     }
     ALOGV("Failed to find image for buffer: %" PRIu64, bufferId);
 }
@@ -842,6 +902,7 @@
                                                              bool useFramebufferCache) {
     sp<GraphicBuffer> graphicBuffer = GraphicBuffer::from(nativeBuffer);
     if (useFramebufferCache) {
+        std::lock_guard<std::mutex> lock(mFramebufferImageCacheMutex);
         for (const auto& image : mFramebufferImageCache) {
             if (image.first == graphicBuffer->getId()) {
                 return image.second;
@@ -857,14 +918,20 @@
                                           nativeBuffer, attributes);
     if (useFramebufferCache) {
         if (image != EGL_NO_IMAGE_KHR) {
+            std::lock_guard<std::mutex> lock(mFramebufferImageCacheMutex);
             if (mFramebufferImageCache.size() >= mFramebufferImageCacheSize) {
                 EGLImageKHR expired = mFramebufferImageCache.front().second;
                 mFramebufferImageCache.pop_front();
                 eglDestroyImageKHR(mEGLDisplay, expired);
+                DEBUG_EGL_IMAGE_TRACKER_DESTROY();
             }
             mFramebufferImageCache.push_back({graphicBuffer->getId(), image});
         }
     }
+
+    if (image != EGL_NO_IMAGE_KHR) {
+        DEBUG_EGL_IMAGE_TRACKER_CREATE();
+    }
     return image;
 }
 
@@ -889,127 +956,123 @@
         return BAD_VALUE;
     }
 
-    {
-        std::lock_guard<std::mutex> lock(mRenderingMutex);
+    BindNativeBufferAsFramebuffer fbo(*this, buffer, useFramebufferCache);
 
-        BindNativeBufferAsFramebuffer fbo(*this, buffer, useFramebufferCache);
-
-        if (fbo.getStatus() != NO_ERROR) {
-            ALOGE("Failed to bind framebuffer! Aborting GPU composition for buffer (%p).",
-                  buffer->handle);
-            checkErrors();
-            return fbo.getStatus();
-        }
-
-        // clear the entire buffer, sometimes when we reuse buffers we'd persist
-        // ghost images otherwise.
-        // we also require a full transparent framebuffer for overlays. This is
-        // probably not quite efficient on all GPUs, since we could filter out
-        // opaque layers.
-        clearWithColor(0.0, 0.0, 0.0, 0.0);
-
-        setViewportAndProjection(display.physicalDisplay, display.clip);
-
-        setOutputDataSpace(display.outputDataspace);
-        setDisplayMaxLuminance(display.maxLuminance);
-
-        mat4 projectionMatrix = mState.projectionMatrix * display.globalTransform;
-        mState.projectionMatrix = projectionMatrix;
-        if (!display.clearRegion.isEmpty()) {
-            glDisable(GL_BLEND);
-            fillRegionWithColor(display.clearRegion, 0.0, 0.0, 0.0, 1.0);
-        }
-
-        Mesh mesh(Mesh::TRIANGLE_FAN, 4, 2, 2);
-        for (auto layer : layers) {
-            mState.projectionMatrix = projectionMatrix * layer.geometry.positionTransform;
-
-            const FloatRect bounds = layer.geometry.boundaries;
-            Mesh::VertexArray<vec2> position(mesh.getPositionArray<vec2>());
-            position[0] = vec2(bounds.left, bounds.top);
-            position[1] = vec2(bounds.left, bounds.bottom);
-            position[2] = vec2(bounds.right, bounds.bottom);
-            position[3] = vec2(bounds.right, bounds.top);
-
-            setupLayerCropping(layer, mesh);
-            setColorTransform(display.colorTransform * layer.colorTransform);
-
-            bool usePremultipliedAlpha = true;
-            bool disableTexture = true;
-            bool isOpaque = false;
-
-            if (layer.source.buffer.buffer != nullptr) {
-                disableTexture = false;
-                isOpaque = layer.source.buffer.isOpaque;
-
-                sp<GraphicBuffer> gBuf = layer.source.buffer.buffer;
-                bindExternalTextureBufferLocked(layer.source.buffer.textureName, gBuf,
-                                                layer.source.buffer.fence);
-
-                usePremultipliedAlpha = layer.source.buffer.usePremultipliedAlpha;
-                Texture texture(Texture::TEXTURE_EXTERNAL, layer.source.buffer.textureName);
-                mat4 texMatrix = layer.source.buffer.textureTransform;
-
-                texture.setMatrix(texMatrix.asArray());
-                texture.setFiltering(layer.source.buffer.useTextureFiltering);
-
-                texture.setDimensions(gBuf->getWidth(), gBuf->getHeight());
-                setSourceY410BT2020(layer.source.buffer.isY410BT2020);
-
-                renderengine::Mesh::VertexArray<vec2> texCoords(mesh.getTexCoordArray<vec2>());
-                texCoords[0] = vec2(0.0, 0.0);
-                texCoords[1] = vec2(0.0, 1.0);
-                texCoords[2] = vec2(1.0, 1.0);
-                texCoords[3] = vec2(1.0, 0.0);
-                setupLayerTexturing(texture);
-            }
-
-            const half3 solidColor = layer.source.solidColor;
-            const half4 color = half4(solidColor.r, solidColor.g, solidColor.b, layer.alpha);
-            // Buffer sources will have a black solid color ignored in the shader,
-            // so in that scenario the solid color passed here is arbitrary.
-            setupLayerBlending(usePremultipliedAlpha, isOpaque, disableTexture, color,
-                               layer.geometry.roundedCornersRadius);
-            if (layer.disableBlending) {
-                glDisable(GL_BLEND);
-            }
-            setSourceDataSpace(layer.sourceDataspace);
-
-            // We only want to do a special handling for rounded corners when having rounded corners
-            // is the only reason it needs to turn on blending, otherwise, we handle it like the
-            // usual way since it needs to turn on blending anyway.
-            if (layer.geometry.roundedCornersRadius > 0.0 && color.a >= 1.0f && isOpaque) {
-                handleRoundedCorners(display, layer, mesh);
-            } else {
-                drawMesh(mesh);
-            }
-
-            // Cleanup if there's a buffer source
-            if (layer.source.buffer.buffer != nullptr) {
-                disableBlending();
-                setSourceY410BT2020(false);
-                disableTexturing();
-            }
-        }
-
-        if (drawFence != nullptr) {
-            *drawFence = flush();
-        }
-        // If flush failed or we don't support native fences, we need to force the
-        // gl command stream to be executed.
-        if (drawFence == nullptr || drawFence->get() < 0) {
-            bool success = finish();
-            if (!success) {
-                ALOGE("Failed to flush RenderEngine commands");
-                checkErrors();
-                // Chances are, something illegal happened (either the caller passed
-                // us bad parameters, or we messed up our shader generation).
-                return INVALID_OPERATION;
-            }
-        }
-
+    if (fbo.getStatus() != NO_ERROR) {
+        ALOGE("Failed to bind framebuffer! Aborting GPU composition for buffer (%p).",
+              buffer->handle);
         checkErrors();
+        return fbo.getStatus();
     }
+
+    // clear the entire buffer, sometimes when we reuse buffers we'd persist
+    // ghost images otherwise.
+    // we also require a full transparent framebuffer for overlays. This is
+    // probably not quite efficient on all GPUs, since we could filter out
+    // opaque layers.
+    clearWithColor(0.0, 0.0, 0.0, 0.0);
+
+    setViewportAndProjection(display.physicalDisplay, display.clip);
+
+    setOutputDataSpace(display.outputDataspace);
+    setDisplayMaxLuminance(display.maxLuminance);
+
+    mat4 projectionMatrix = mState.projectionMatrix * display.globalTransform;
+    mState.projectionMatrix = projectionMatrix;
+    if (!display.clearRegion.isEmpty()) {
+        glDisable(GL_BLEND);
+        fillRegionWithColor(display.clearRegion, 0.0, 0.0, 0.0, 1.0);
+    }
+
+    Mesh mesh(Mesh::TRIANGLE_FAN, 4, 2, 2);
+    for (auto layer : layers) {
+        mState.projectionMatrix = projectionMatrix * layer.geometry.positionTransform;
+
+        const FloatRect bounds = layer.geometry.boundaries;
+        Mesh::VertexArray<vec2> position(mesh.getPositionArray<vec2>());
+        position[0] = vec2(bounds.left, bounds.top);
+        position[1] = vec2(bounds.left, bounds.bottom);
+        position[2] = vec2(bounds.right, bounds.bottom);
+        position[3] = vec2(bounds.right, bounds.top);
+
+        setupLayerCropping(layer, mesh);
+        setColorTransform(display.colorTransform * layer.colorTransform);
+
+        bool usePremultipliedAlpha = true;
+        bool disableTexture = true;
+        bool isOpaque = false;
+
+        if (layer.source.buffer.buffer != nullptr) {
+            disableTexture = false;
+            isOpaque = layer.source.buffer.isOpaque;
+
+            sp<GraphicBuffer> gBuf = layer.source.buffer.buffer;
+            bindExternalTextureBuffer(layer.source.buffer.textureName, gBuf,
+                                      layer.source.buffer.fence);
+
+            usePremultipliedAlpha = layer.source.buffer.usePremultipliedAlpha;
+            Texture texture(Texture::TEXTURE_EXTERNAL, layer.source.buffer.textureName);
+            mat4 texMatrix = layer.source.buffer.textureTransform;
+
+            texture.setMatrix(texMatrix.asArray());
+            texture.setFiltering(layer.source.buffer.useTextureFiltering);
+
+            texture.setDimensions(gBuf->getWidth(), gBuf->getHeight());
+            setSourceY410BT2020(layer.source.buffer.isY410BT2020);
+
+            renderengine::Mesh::VertexArray<vec2> texCoords(mesh.getTexCoordArray<vec2>());
+            texCoords[0] = vec2(0.0, 0.0);
+            texCoords[1] = vec2(0.0, 1.0);
+            texCoords[2] = vec2(1.0, 1.0);
+            texCoords[3] = vec2(1.0, 0.0);
+            setupLayerTexturing(texture);
+        }
+
+        const half3 solidColor = layer.source.solidColor;
+        const half4 color = half4(solidColor.r, solidColor.g, solidColor.b, layer.alpha);
+        // Buffer sources will have a black solid color ignored in the shader,
+        // so in that scenario the solid color passed here is arbitrary.
+        setupLayerBlending(usePremultipliedAlpha, isOpaque, disableTexture, color,
+                           layer.geometry.roundedCornersRadius);
+        if (layer.disableBlending) {
+            glDisable(GL_BLEND);
+        }
+        setSourceDataSpace(layer.sourceDataspace);
+
+        // We only want to do a special handling for rounded corners when having rounded corners
+        // is the only reason it needs to turn on blending, otherwise, we handle it like the
+        // usual way since it needs to turn on blending anyway.
+        if (layer.geometry.roundedCornersRadius > 0.0 && color.a >= 1.0f && isOpaque) {
+            handleRoundedCorners(display, layer, mesh);
+        } else {
+            drawMesh(mesh);
+        }
+
+        // Cleanup if there's a buffer source
+        if (layer.source.buffer.buffer != nullptr) {
+            disableBlending();
+            setSourceY410BT2020(false);
+            disableTexturing();
+        }
+    }
+
+    if (drawFence != nullptr) {
+        *drawFence = flush();
+    }
+    // If flush failed or we don't support native fences, we need to force the
+    // gl command stream to be executed.
+    if (drawFence == nullptr || drawFence->get() < 0) {
+        bool success = finish();
+        if (!success) {
+            ALOGE("Failed to flush RenderEngine commands");
+            checkErrors();
+            // Chances are, something illegal happened (either the caller passed
+            // us bad parameters, or we messed up our shader generation).
+            return INVALID_OPERATION;
+        }
+    }
+
+    checkErrors();
     return NO_ERROR;
 }
 
@@ -1306,6 +1369,23 @@
     StringAppendF(&result, "RenderEngine last dataspace conversion: (%s) to (%s)\n",
                   dataspaceDetails(static_cast<android_dataspace>(mDataSpace)).c_str(),
                   dataspaceDetails(static_cast<android_dataspace>(mOutputDataSpace)).c_str());
+    {
+        std::lock_guard<std::mutex> lock(mRenderingMutex);
+        StringAppendF(&result, "RenderEngine image cache size: %zu\n", mImageCache.size());
+        StringAppendF(&result, "Dumping buffer ids...\n");
+        for (const auto& [id, unused] : mImageCache) {
+            StringAppendF(&result, "0x%" PRIx64 "\n", id);
+        }
+    }
+    {
+        std::lock_guard<std::mutex> lock(mFramebufferImageCacheMutex);
+        StringAppendF(&result, "RenderEngine framebuffer image cache size: %zu\n",
+                      mFramebufferImageCache.size());
+        StringAppendF(&result, "Dumping buffer ids...\n");
+        for (const auto& [id, unused] : mFramebufferImageCache) {
+            StringAppendF(&result, "0x%" PRIx64 "\n", id);
+        }
+    }
 }
 
 GLESRenderEngine::GlesVersion GLESRenderEngine::parseGlesVersion(const char* str) {
@@ -1432,7 +1512,7 @@
 }
 
 bool GLESRenderEngine::isFramebufferImageCachedForTesting(uint64_t bufferId) {
-    std::lock_guard<std::mutex> lock(mRenderingMutex);
+    std::lock_guard<std::mutex> lock(mFramebufferImageCacheMutex);
     return std::any_of(mFramebufferImageCache.cbegin(), mFramebufferImageCache.cend(),
                        [=](std::pair<uint64_t, EGLImageKHR> image) {
                            return image.first == bufferId;
diff --git a/libs/renderengine/gl/GLESRenderEngine.h b/libs/renderengine/gl/GLESRenderEngine.h
index de793c2..dd60e50 100644
--- a/libs/renderengine/gl/GLESRenderEngine.h
+++ b/libs/renderengine/gl/GLESRenderEngine.h
@@ -17,9 +17,7 @@
 #ifndef SF_GLESRENDERENGINE_H_
 #define SF_GLESRENDERENGINE_H_
 
-#include <android-base/thread_annotations.h>
 #include <stdint.h>
-#include <sys/types.h>
 #include <condition_variable>
 #include <deque>
 #include <mutex>
@@ -30,8 +28,11 @@
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
 #include <GLES2/gl2.h>
+#include <android-base/thread_annotations.h>
 #include <renderengine/RenderEngine.h>
 #include <renderengine/private/Description.h>
+#include <sys/types.h>
+#include "ImageManager.h"
 
 #define EGL_NO_CONFIG ((EGLConfig)0)
 
@@ -74,7 +75,7 @@
     void bindExternalTextureImage(uint32_t texName, const Image& image) override;
     status_t bindExternalTextureBuffer(uint32_t texName, const sp<GraphicBuffer>& buffer,
                                        const sp<Fence>& fence) EXCLUDES(mRenderingMutex);
-    status_t cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) EXCLUDES(mRenderingMutex);
+    void cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) EXCLUDES(mRenderingMutex);
     void unbindExternalTextureBuffer(uint64_t bufferId) EXCLUDES(mRenderingMutex);
     status_t bindFrameBuffer(Framebuffer* framebuffer) override;
     void unbindFrameBuffer(Framebuffer* framebuffer) override;
@@ -85,25 +86,32 @@
     bool useProtectedContext(bool useProtectedContext) override;
     status_t drawLayers(const DisplaySettings& display, const std::vector<LayerSettings>& layers,
                         ANativeWindowBuffer* buffer, const bool useFramebufferCache,
-                        base::unique_fd&& bufferFence, base::unique_fd* drawFence)
-            EXCLUDES(mRenderingMutex) override;
+                        base::unique_fd&& bufferFence, base::unique_fd* drawFence) override;
 
     // internal to RenderEngine
     EGLDisplay getEGLDisplay() const { return mEGLDisplay; }
     EGLConfig getEGLConfig() const { return mEGLConfig; }
     // Creates an output image for rendering to
     EGLImageKHR createFramebufferImageIfNeeded(ANativeWindowBuffer* nativeBuffer, bool isProtected,
-                                               bool useFramebufferCache);
+                                               bool useFramebufferCache)
+            EXCLUDES(mFramebufferImageCacheMutex);
 
     // Test-only methods
     // Returns true iff mImageCache contains an image keyed by bufferId
     bool isImageCachedForTesting(uint64_t bufferId) EXCLUDES(mRenderingMutex);
     // Returns true iff mFramebufferImageCache contains an image keyed by bufferId
-    bool isFramebufferImageCachedForTesting(uint64_t bufferId) EXCLUDES(mRenderingMutex);
+    bool isFramebufferImageCachedForTesting(uint64_t bufferId)
+            EXCLUDES(mFramebufferImageCacheMutex);
+    // These are wrappers around public methods above, but exposing Barrier
+    // objects so that tests can block.
+    std::shared_ptr<ImageManager::Barrier> cacheExternalTextureBufferForTesting(
+            const sp<GraphicBuffer>& buffer);
+    std::shared_ptr<ImageManager::Barrier> unbindExternalTextureBufferForTesting(uint64_t bufferId);
 
 protected:
     Framebuffer* getFramebufferForDrawing() override;
-    void dump(std::string& result) override;
+    void dump(std::string& result) override EXCLUDES(mRenderingMutex)
+            EXCLUDES(mFramebufferImageCacheMutex);
     void setViewportAndProjection(size_t vpw, size_t vph, Rect sourceCrop,
                                   ui::Transform::orientation_flags rotation) override;
     void setupLayerBlending(bool premultipliedAlpha, bool opaque, bool disableTexture,
@@ -145,6 +153,9 @@
     void setScissor(const Rect& region);
     void disableScissor();
     bool waitSync(EGLSyncKHR sync, EGLint flags);
+    status_t cacheExternalTextureBufferInternal(const sp<GraphicBuffer>& buffer)
+            EXCLUDES(mRenderingMutex);
+    void unbindExternalTextureBufferInternal(uint64_t bufferId) EXCLUDES(mRenderingMutex);
 
     // A data space is considered HDR data space if it has BT2020 color space
     // with PQ or HLG transfer function.
@@ -200,7 +211,11 @@
     uint32_t mFramebufferImageCacheSize = 0;
 
     // Cache of output images, keyed by corresponding GraphicBuffer ID.
-    std::deque<std::pair<uint64_t, EGLImageKHR>> mFramebufferImageCache;
+    std::deque<std::pair<uint64_t, EGLImageKHR>> mFramebufferImageCache
+            GUARDED_BY(mFramebufferImageCacheMutex);
+    // The only reason why we have this mutex is so that we don't segfault when
+    // dumping info.
+    std::mutex mFramebufferImageCacheMutex;
 
     // Current dataspace of layer being rendered
     ui::Dataspace mDataSpace = ui::Dataspace::UNKNOWN;
@@ -220,15 +235,6 @@
     // multiple threads is guaranteed thread-safe.
     std::mutex mRenderingMutex;
 
-    // See bindExternalTextureBuffer above, but requiring that mRenderingMutex
-    // is held.
-    status_t bindExternalTextureBufferLocked(uint32_t texName, const sp<GraphicBuffer>& buffer,
-                                             const sp<Fence>& fence) REQUIRES(mRenderingMutex);
-    // See cacheExternalTextureBuffer above, but requiring that mRenderingMutex
-    // is held.
-    status_t cacheExternalTextureBufferLocked(const sp<GraphicBuffer>& buffer)
-            REQUIRES(mRenderingMutex);
-
     std::unique_ptr<Framebuffer> mDrawingBuffer;
 
     class FlushTracer {
@@ -253,7 +259,9 @@
         bool mRunning = true;
     };
     friend class FlushTracer;
+    friend class ImageManager;
     std::unique_ptr<FlushTracer> mFlushTracer;
+    std::unique_ptr<ImageManager> mImageManager = std::make_unique<ImageManager>(this);
 };
 
 } // namespace gl
diff --git a/libs/renderengine/gl/GLFramebuffer.cpp b/libs/renderengine/gl/GLFramebuffer.cpp
index dacf8d3..5fbb5ba 100644
--- a/libs/renderengine/gl/GLFramebuffer.cpp
+++ b/libs/renderengine/gl/GLFramebuffer.cpp
@@ -22,6 +22,7 @@
 #include <GLES/glext.h>
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
+#include <gui/DebugEGLImageTracker.h>
 #include <nativebase/nativebase.h>
 #include <utils/Trace.h>
 #include "GLESRenderEngine.h"
@@ -47,6 +48,7 @@
     if (mEGLImage != EGL_NO_IMAGE_KHR) {
         if (!usingFramebufferCache) {
             eglDestroyImageKHR(mEGLDisplay, mEGLImage);
+            DEBUG_EGL_IMAGE_TRACKER_DESTROY();
         }
         mEGLImage = EGL_NO_IMAGE_KHR;
         mBufferWidth = 0;
diff --git a/libs/renderengine/gl/GLImage.cpp b/libs/renderengine/gl/GLImage.cpp
index 77e648e..8497721 100644
--- a/libs/renderengine/gl/GLImage.cpp
+++ b/libs/renderengine/gl/GLImage.cpp
@@ -20,6 +20,7 @@
 
 #include <vector>
 
+#include <gui/DebugEGLImageTracker.h>
 #include <log/log.h>
 #include <utils/Trace.h>
 #include "GLESRenderEngine.h"
@@ -58,6 +59,7 @@
         if (!eglDestroyImageKHR(mEGLDisplay, mEGLImage)) {
             ALOGE("failed to destroy image: %#x", eglGetError());
         }
+        DEBUG_EGL_IMAGE_TRACKER_DESTROY();
         mEGLImage = EGL_NO_IMAGE_KHR;
     }
 
@@ -69,6 +71,7 @@
             ALOGE("failed to create EGLImage: %#x", eglGetError());
             return false;
         }
+        DEBUG_EGL_IMAGE_TRACKER_CREATE();
         mProtected = isProtected;
     }
 
diff --git a/libs/renderengine/gl/ImageManager.cpp b/libs/renderengine/gl/ImageManager.cpp
new file mode 100644
index 0000000..5af0e4f
--- /dev/null
+++ b/libs/renderengine/gl/ImageManager.cpp
@@ -0,0 +1,140 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
+#include <pthread.h>
+
+#include <processgroup/sched_policy.h>
+#include <utils/Trace.h>
+#include "GLESRenderEngine.h"
+#include "ImageManager.h"
+
+namespace android {
+namespace renderengine {
+namespace gl {
+
+ImageManager::ImageManager(GLESRenderEngine* engine) : mEngine(engine) {
+    pthread_setname_np(mThread.native_handle(), "ImageManager");
+    // Use SCHED_FIFO to minimize jitter
+    struct sched_param param = {0};
+    param.sched_priority = 2;
+    if (pthread_setschedparam(mThread.native_handle(), SCHED_FIFO, &param) != 0) {
+        ALOGE("Couldn't set SCHED_FIFO for ImageManager");
+    }
+}
+
+ImageManager::~ImageManager() {
+    {
+        std::lock_guard<std::mutex> lock(mMutex);
+        mRunning = false;
+    }
+    mCondition.notify_all();
+    if (mThread.joinable()) {
+        mThread.join();
+    }
+}
+
+void ImageManager::cacheAsync(const sp<GraphicBuffer>& buffer,
+                              const std::shared_ptr<Barrier>& barrier) {
+    if (buffer == nullptr) {
+        {
+            std::lock_guard<std::mutex> lock(barrier->mutex);
+            barrier->isOpen = true;
+            barrier->result = BAD_VALUE;
+        }
+        barrier->condition.notify_one();
+        return;
+    }
+    ATRACE_CALL();
+    QueueEntry entry = {QueueEntry::Operation::Insert, buffer, buffer->getId(), barrier};
+    queueOperation(std::move(entry));
+}
+
+status_t ImageManager::cache(const sp<GraphicBuffer>& buffer) {
+    ATRACE_CALL();
+    auto barrier = std::make_shared<Barrier>();
+    cacheAsync(buffer, barrier);
+    std::lock_guard<std::mutex> lock(barrier->mutex);
+    barrier->condition.wait(barrier->mutex,
+                            [&]() REQUIRES(barrier->mutex) { return barrier->isOpen; });
+    return barrier->result;
+}
+
+void ImageManager::releaseAsync(uint64_t bufferId, const std::shared_ptr<Barrier>& barrier) {
+    ATRACE_CALL();
+    QueueEntry entry = {QueueEntry::Operation::Delete, nullptr, bufferId, barrier};
+    queueOperation(std::move(entry));
+}
+
+void ImageManager::queueOperation(const QueueEntry&& entry) {
+    {
+        std::lock_guard<std::mutex> lock(mMutex);
+        mQueue.emplace(entry);
+        ATRACE_INT("ImageManagerQueueDepth", mQueue.size());
+    }
+    mCondition.notify_one();
+}
+
+void ImageManager::threadMain() {
+    set_sched_policy(0, SP_FOREGROUND);
+    bool run;
+    {
+        std::lock_guard<std::mutex> lock(mMutex);
+        run = mRunning;
+    }
+    while (run) {
+        QueueEntry entry;
+        {
+            std::lock_guard<std::mutex> lock(mMutex);
+            mCondition.wait(mMutex,
+                            [&]() REQUIRES(mMutex) { return !mQueue.empty() || !mRunning; });
+            run = mRunning;
+
+            if (!mRunning) {
+                // if mRunning is false, then ImageManager is being destroyed, so
+                // bail out now.
+                break;
+            }
+
+            entry = mQueue.front();
+            mQueue.pop();
+            ATRACE_INT("ImageManagerQueueDepth", mQueue.size());
+        }
+
+        status_t result = NO_ERROR;
+        switch (entry.op) {
+            case QueueEntry::Operation::Delete:
+                mEngine->unbindExternalTextureBufferInternal(entry.bufferId);
+                break;
+            case QueueEntry::Operation::Insert:
+                result = mEngine->cacheExternalTextureBufferInternal(entry.buffer);
+                break;
+        }
+        if (entry.barrier != nullptr) {
+            {
+                std::lock_guard<std::mutex> entryLock(entry.barrier->mutex);
+                entry.barrier->result = result;
+                entry.barrier->isOpen = true;
+            }
+            entry.barrier->condition.notify_one();
+        }
+    }
+}
+
+} // namespace gl
+} // namespace renderengine
+} // namespace android
diff --git a/libs/renderengine/gl/ImageManager.h b/libs/renderengine/gl/ImageManager.h
new file mode 100644
index 0000000..b5ba554
--- /dev/null
+++ b/libs/renderengine/gl/ImageManager.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <condition_variable>
+#include <mutex>
+#include <queue>
+#include <thread>
+
+#include <ui/GraphicBuffer.h>
+
+namespace android {
+namespace renderengine {
+namespace gl {
+
+class GLESRenderEngine;
+
+class ImageManager {
+public:
+    struct Barrier {
+        std::mutex mutex;
+        std::condition_variable_any condition;
+        bool isOpen GUARDED_BY(mutex) = false;
+        status_t result GUARDED_BY(mutex) = NO_ERROR;
+    };
+    ImageManager(GLESRenderEngine* engine);
+    ~ImageManager();
+    void cacheAsync(const sp<GraphicBuffer>& buffer, const std::shared_ptr<Barrier>& barrier)
+            EXCLUDES(mMutex);
+    status_t cache(const sp<GraphicBuffer>& buffer);
+    void releaseAsync(uint64_t bufferId, const std::shared_ptr<Barrier>& barrier) EXCLUDES(mMutex);
+
+private:
+    struct QueueEntry {
+        enum class Operation { Delete, Insert };
+
+        Operation op = Operation::Delete;
+        sp<GraphicBuffer> buffer = nullptr;
+        uint64_t bufferId = 0;
+        std::shared_ptr<Barrier> barrier = nullptr;
+    };
+
+    void queueOperation(const QueueEntry&& entry);
+    void threadMain();
+    GLESRenderEngine* const mEngine;
+    std::thread mThread = std::thread([this]() { threadMain(); });
+    std::condition_variable_any mCondition;
+    std::mutex mMutex;
+    std::queue<QueueEntry> mQueue GUARDED_BY(mMutex);
+
+    bool mRunning GUARDED_BY(mMutex) = true;
+};
+
+} // namespace gl
+} // namespace renderengine
+} // namespace android
diff --git a/libs/renderengine/include/renderengine/RenderEngine.h b/libs/renderengine/include/renderengine/RenderEngine.h
index e707004..c6a7bd8 100644
--- a/libs/renderengine/include/renderengine/RenderEngine.h
+++ b/libs/renderengine/include/renderengine/RenderEngine.h
@@ -116,10 +116,20 @@
                                                const sp<Fence>& fence) = 0;
     // Caches Image resources for this buffer, but does not bind the buffer to
     // a particular texture.
-    virtual status_t cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) = 0;
+    // Note that work is deferred to an additional thread, i.e. this call
+    // is made asynchronously, but the caller can expect that cache/unbind calls
+    // are performed in a manner that's conflict serializable, i.e. unbinding
+    // a buffer should never occur before binding the buffer if the caller
+    // called {bind, cache}ExternalTextureBuffer before calling unbind.
+    virtual void cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) = 0;
     // Removes internal resources referenced by the bufferId. This method should be
     // invoked when the caller will no longer hold a reference to a GraphicBuffer
     // and needs to clean up its resources.
+    // Note that work is deferred to an additional thread, i.e. this call
+    // is made asynchronously, but the caller can expect that cache/unbind calls
+    // are performed in a manner that's conflict serializable, i.e. unbinding
+    // a buffer should never occur before binding the buffer if the caller
+    // called {bind, cache}ExternalTextureBuffer before calling unbind.
     virtual void unbindExternalTextureBuffer(uint64_t bufferId) = 0;
     // When binding a native buffer, it must be done before setViewportAndProjection
     // Returns NO_ERROR when binds successfully, NO_MEMORY when there's no memory for allocation.
@@ -176,6 +186,17 @@
     // should be called for every display that needs to be rendered via the GPU.
     // @param display The display-wide settings that should be applied prior to
     // drawing any layers.
+    //
+    // Assumptions when calling this method:
+    // 1. There is exactly one caller - i.e. multi-threading is not supported.
+    // 2. Additional threads may be calling the {bind,cache}ExternalTexture
+    // methods above. But the main thread is responsible for holding resources
+    // such that Image destruction does not occur while this method is called.
+    //
+    // TODO(b/136806342): This should behavior should ideally be fixed since
+    // the above two assumptions are brittle, as conditional thread safetyness
+    // may be insufficient when maximizing rendering performance in the future.
+    //
     // @param layers The layers to draw onto the display, in Z-order.
     // @param buffer The buffer which will be drawn to. This buffer will be
     // ready once drawFence fires.
diff --git a/libs/renderengine/include/renderengine/mock/RenderEngine.h b/libs/renderengine/include/renderengine/mock/RenderEngine.h
index e33bcfd..b4d3ef2 100644
--- a/libs/renderengine/include/renderengine/mock/RenderEngine.h
+++ b/libs/renderengine/include/renderengine/mock/RenderEngine.h
@@ -51,7 +51,7 @@
     MOCK_METHOD2(genTextures, void(size_t, uint32_t*));
     MOCK_METHOD2(deleteTextures, void(size_t, uint32_t const*));
     MOCK_METHOD2(bindExternalTextureImage, void(uint32_t, const renderengine::Image&));
-    MOCK_METHOD1(cacheExternalTextureBuffer, status_t(const sp<GraphicBuffer>&));
+    MOCK_METHOD1(cacheExternalTextureBuffer, void(const sp<GraphicBuffer>&));
     MOCK_METHOD3(bindExternalTextureBuffer,
                  status_t(uint32_t, const sp<GraphicBuffer>&, const sp<Fence>&));
     MOCK_METHOD1(unbindExternalTextureBuffer, void(uint64_t));
diff --git a/libs/renderengine/tests/Android.bp b/libs/renderengine/tests/Android.bp
index 9b483ef..e98babc 100644
--- a/libs/renderengine/tests/Android.bp
+++ b/libs/renderengine/tests/Android.bp
@@ -31,6 +31,7 @@
         "libgui",
         "liblog",
         "libnativewindow",
+        "libprocessgroup",
         "libsync",
         "libui",
         "libutils",
diff --git a/libs/renderengine/tests/RenderEngineTest.cpp b/libs/renderengine/tests/RenderEngineTest.cpp
index 7acaecf..f47c7fd 100644
--- a/libs/renderengine/tests/RenderEngineTest.cpp
+++ b/libs/renderengine/tests/RenderEngineTest.cpp
@@ -14,8 +14,10 @@
  * limitations under the License.
  */
 
-#include <gtest/gtest.h>
+#include <chrono>
+#include <condition_variable>
 
+#include <gtest/gtest.h>
 #include <renderengine/RenderEngine.h>
 #include <sync/sync.h>
 #include <ui/PixelFormat.h>
@@ -1001,8 +1003,15 @@
     invokeDraw(settings, layers, mBuffer);
     uint64_t bufferId = layer.source.buffer.buffer->getId();
     EXPECT_TRUE(sRE->isImageCachedForTesting(bufferId));
-    sRE->unbindExternalTextureBuffer(bufferId);
+    std::shared_ptr<renderengine::gl::ImageManager::Barrier> barrier =
+            sRE->unbindExternalTextureBufferForTesting(bufferId);
+    std::lock_guard<std::mutex> lock(barrier->mutex);
+    ASSERT_TRUE(barrier->condition.wait_for(barrier->mutex, std::chrono::seconds(5),
+                                            [&]() REQUIRES(barrier->mutex) {
+                                                return barrier->isOpen;
+                                            }));
     EXPECT_FALSE(sRE->isImageCachedForTesting(bufferId));
+    EXPECT_EQ(NO_ERROR, barrier->result);
 }
 
 TEST_F(RenderEngineTest, drawLayers_bindExternalBufferWithNullBuffer) {
@@ -1019,21 +1028,52 @@
     sRE->bindExternalTextureBuffer(texName, buf, nullptr);
     uint64_t bufferId = buf->getId();
     EXPECT_TRUE(sRE->isImageCachedForTesting(bufferId));
-    sRE->unbindExternalTextureBuffer(bufferId);
+    std::shared_ptr<renderengine::gl::ImageManager::Barrier> barrier =
+            sRE->unbindExternalTextureBufferForTesting(bufferId);
+    std::lock_guard<std::mutex> lock(barrier->mutex);
+    ASSERT_TRUE(barrier->condition.wait_for(barrier->mutex, std::chrono::seconds(5),
+                                            [&]() REQUIRES(barrier->mutex) {
+                                                return barrier->isOpen;
+                                            }));
+    EXPECT_EQ(NO_ERROR, barrier->result);
     EXPECT_FALSE(sRE->isImageCachedForTesting(bufferId));
 }
 
 TEST_F(RenderEngineTest, drawLayers_cacheExternalBufferWithNullBuffer) {
-    status_t result = sRE->cacheExternalTextureBuffer(nullptr);
-    ASSERT_EQ(BAD_VALUE, result);
+    std::shared_ptr<renderengine::gl::ImageManager::Barrier> barrier =
+            sRE->cacheExternalTextureBufferForTesting(nullptr);
+    std::lock_guard<std::mutex> lock(barrier->mutex);
+    ASSERT_TRUE(barrier->condition.wait_for(barrier->mutex, std::chrono::seconds(5),
+                                            [&]() REQUIRES(barrier->mutex) {
+                                                return barrier->isOpen;
+                                            }));
+    EXPECT_TRUE(barrier->isOpen);
+    EXPECT_EQ(BAD_VALUE, barrier->result);
 }
 
 TEST_F(RenderEngineTest, drawLayers_cacheExternalBufferCachesImages) {
     sp<GraphicBuffer> buf = allocateSourceBuffer(1, 1);
     uint64_t bufferId = buf->getId();
-    sRE->cacheExternalTextureBuffer(buf);
+    std::shared_ptr<renderengine::gl::ImageManager::Barrier> barrier =
+            sRE->cacheExternalTextureBufferForTesting(buf);
+    {
+        std::lock_guard<std::mutex> lock(barrier->mutex);
+        ASSERT_TRUE(barrier->condition.wait_for(barrier->mutex, std::chrono::seconds(5),
+                                                [&]() REQUIRES(barrier->mutex) {
+                                                    return barrier->isOpen;
+                                                }));
+        EXPECT_EQ(NO_ERROR, barrier->result);
+    }
     EXPECT_TRUE(sRE->isImageCachedForTesting(bufferId));
-    sRE->unbindExternalTextureBuffer(bufferId);
+    barrier = sRE->unbindExternalTextureBufferForTesting(bufferId);
+    {
+        std::lock_guard<std::mutex> lock(barrier->mutex);
+        ASSERT_TRUE(barrier->condition.wait_for(barrier->mutex, std::chrono::seconds(5),
+                                                [&]() REQUIRES(barrier->mutex) {
+                                                    return barrier->isOpen;
+                                                }));
+        EXPECT_EQ(NO_ERROR, barrier->result);
+    }
     EXPECT_FALSE(sRE->isImageCachedForTesting(bufferId));
 }
 
diff --git a/libs/ui/GraphicBufferAllocator.cpp b/libs/ui/GraphicBufferAllocator.cpp
index 0861a1f..9c7d1fd 100644
--- a/libs/ui/GraphicBufferAllocator.cpp
+++ b/libs/ui/GraphicBufferAllocator.cpp
@@ -20,6 +20,7 @@
 
 #include <ui/GraphicBufferAllocator.h>
 
+#include <limits.h>
 #include <stdio.h>
 
 #include <grallocusage/GrallocUsageConversion.h>
@@ -114,6 +115,14 @@
     if (!width || !height)
         width = height = 1;
 
+    const uint32_t bpp = bytesPerPixel(format);
+    if (std::numeric_limits<size_t>::max() / width / height < static_cast<size_t>(bpp)) {
+        ALOGE("Failed to allocate (%u x %u) layerCount %u format %d "
+              "usage %" PRIx64 ": Requesting too large a buffer size",
+              width, height, layerCount, format, usage);
+        return BAD_VALUE;
+    }
+
     // Ensure that layerCount is valid.
     if (layerCount < 1)
         layerCount = 1;
@@ -126,7 +135,6 @@
     if (error == NO_ERROR) {
         Mutex::Autolock _l(sLock);
         KeyedVector<buffer_handle_t, alloc_rec_t>& list(sAllocList);
-        uint32_t bpp = bytesPerPixel(format);
         alloc_rec_t rec;
         rec.width = width;
         rec.height = height;
diff --git a/libs/ui/tests/GraphicBuffer_test.cpp b/libs/ui/tests/GraphicBuffer_test.cpp
index a7c248c..127f7ee 100644
--- a/libs/ui/tests/GraphicBuffer_test.cpp
+++ b/libs/ui/tests/GraphicBuffer_test.cpp
@@ -35,6 +35,22 @@
 
 class GraphicBufferTest : public testing::Test {};
 
+TEST_F(GraphicBufferTest, AllocateNoError) {
+    PixelFormat format = PIXEL_FORMAT_RGBA_8888;
+    sp<GraphicBuffer> gb(new GraphicBuffer(kTestWidth, kTestHeight, format, kTestLayerCount,
+                                           kTestUsage, std::string("test")));
+    ASSERT_EQ(NO_ERROR, gb->initCheck());
+}
+
+TEST_F(GraphicBufferTest, AllocateBadDimensions) {
+    PixelFormat format = PIXEL_FORMAT_RGBA_8888;
+    uint32_t width, height;
+    width = height = std::numeric_limits<uint32_t>::max();
+    sp<GraphicBuffer> gb(new GraphicBuffer(width, height, format, kTestLayerCount, kTestUsage,
+                                           std::string("test")));
+    ASSERT_EQ(BAD_VALUE, gb->initCheck());
+}
+
 TEST_F(GraphicBufferTest, CreateFromBufferHubBuffer) {
     std::unique_ptr<BufferHubBuffer> b1 =
             BufferHubBuffer::create(kTestWidth, kTestHeight, kTestLayerCount, kTestFormat,
diff --git a/services/inputflinger/InputClassifier.cpp b/services/inputflinger/InputClassifier.cpp
index ef1a224..6a7f279 100644
--- a/services/inputflinger/InputClassifier.cpp
+++ b/services/inputflinger/InputClassifier.cpp
@@ -82,7 +82,7 @@
 // Check if the "deep touch" feature is on.
 static bool deepPressEnabled() {
     std::string flag_value = server_configurable_flags::GetServerConfigurableFlag(
-            INPUT_NATIVE_BOOT, DEEP_PRESS_ENABLED, "true");
+            INPUT_NATIVE_BOOT, DEEP_PRESS_ENABLED, "false");
     std::transform(flag_value.begin(), flag_value.end(), flag_value.begin(), ::tolower);
     if (flag_value == "1" || flag_value == "true") {
         ALOGI("Deep press feature enabled.");
diff --git a/services/surfaceflinger/Android.bp b/services/surfaceflinger/Android.bp
index 9aa4e85..5b298b4 100644
--- a/services/surfaceflinger/Android.bp
+++ b/services/surfaceflinger/Android.bp
@@ -153,9 +153,10 @@
         "Scheduler/LayerHistory.cpp",
         "Scheduler/LayerInfo.cpp",
         "Scheduler/MessageQueue.cpp",
+        "Scheduler/PhaseOffsets.cpp",
         "Scheduler/Scheduler.cpp",
         "Scheduler/SchedulerUtils.cpp",
-        "Scheduler/PhaseOffsets.cpp",
+        "Scheduler/VSyncModulator.cpp",
         "StartPropertySetThread.cpp",
         "SurfaceFlinger.cpp",
         "SurfaceInterceptor.cpp",
diff --git a/services/surfaceflinger/BufferLayer.h b/services/surfaceflinger/BufferLayer.h
index b679380..46a62ed 100644
--- a/services/surfaceflinger/BufferLayer.h
+++ b/services/surfaceflinger/BufferLayer.h
@@ -48,7 +48,7 @@
 class BufferLayer : public Layer {
 public:
     explicit BufferLayer(const LayerCreationArgs& args);
-    ~BufferLayer() override;
+    virtual ~BufferLayer() override;
 
     // -----------------------------------------------------------------------
     // Overriden from Layer
diff --git a/services/surfaceflinger/BufferLayerConsumer.cpp b/services/surfaceflinger/BufferLayerConsumer.cpp
index 6709fb4..414814a 100644
--- a/services/surfaceflinger/BufferLayerConsumer.cpp
+++ b/services/surfaceflinger/BufferLayerConsumer.cpp
@@ -369,6 +369,15 @@
     return mCurrentSurfaceDamage;
 }
 
+void BufferLayerConsumer::mergeSurfaceDamage(const Region& damage) {
+    if (damage.bounds() == Rect::INVALID_RECT ||
+        mCurrentSurfaceDamage.bounds() == Rect::INVALID_RECT) {
+        mCurrentSurfaceDamage = Region::INVALID_REGION;
+    } else {
+        mCurrentSurfaceDamage |= damage;
+    }
+}
+
 int BufferLayerConsumer::getCurrentApi() const {
     Mutex::Autolock lock(mMutex);
     return mCurrentApi;
@@ -485,7 +494,6 @@
         if (oldImage == nullptr || oldImage->graphicBuffer() == nullptr ||
             oldImage->graphicBuffer()->getId() != item.mGraphicBuffer->getId()) {
             mImages[item.mSlot] = std::make_shared<Image>(item.mGraphicBuffer, mRE);
-            mRE.cacheExternalTextureBuffer(item.mGraphicBuffer);
         }
     }
 }
@@ -522,6 +530,12 @@
     ConsumerBase::dumpLocked(result, prefix);
 }
 
+BufferLayerConsumer::Image::Image(const sp<GraphicBuffer>& graphicBuffer,
+                                  renderengine::RenderEngine& engine)
+      : mGraphicBuffer(graphicBuffer), mRE(engine) {
+    mRE.cacheExternalTextureBuffer(mGraphicBuffer);
+}
+
 BufferLayerConsumer::Image::~Image() {
     if (mGraphicBuffer != nullptr) {
         ALOGV("Destroying buffer: %" PRId64, mGraphicBuffer->getId());
diff --git a/services/surfaceflinger/BufferLayerConsumer.h b/services/surfaceflinger/BufferLayerConsumer.h
index e3f6100..617b1c2 100644
--- a/services/surfaceflinger/BufferLayerConsumer.h
+++ b/services/surfaceflinger/BufferLayerConsumer.h
@@ -140,6 +140,9 @@
     // must be called from SF main thread
     const Region& getSurfaceDamage() const;
 
+    // Merge the given damage region into the current damage region value.
+    void mergeSurfaceDamage(const Region& damage);
+
     // getCurrentApi retrieves the API which queues the current buffer.
     int getCurrentApi() const;
 
@@ -220,8 +223,7 @@
     // Utility class for managing GraphicBuffer references into renderengine
     class Image {
     public:
-        Image(sp<GraphicBuffer> graphicBuffer, renderengine::RenderEngine& engine)
-              : mGraphicBuffer(graphicBuffer), mRE(engine) {}
+        Image(const sp<GraphicBuffer>& graphicBuffer, renderengine::RenderEngine& engine);
         virtual ~Image();
         const sp<GraphicBuffer>& graphicBuffer() { return mGraphicBuffer; }
 
diff --git a/services/surfaceflinger/BufferQueueLayer.cpp b/services/surfaceflinger/BufferQueueLayer.cpp
index bd0b55f..f35a4fd 100644
--- a/services/surfaceflinger/BufferQueueLayer.cpp
+++ b/services/surfaceflinger/BufferQueueLayer.cpp
@@ -143,7 +143,7 @@
     }
 
     Mutex::Autolock lock(mQueueItemLock);
-    return mQueueItems[0].mTimestamp <= mFlinger->mScheduler->expectedPresentTime();
+    return mQueueItems[0].mTimestamp <= mFlinger->getExpectedPresentTime();
 }
 
 nsecs_t BufferQueueLayer::getDesiredPresentTime() {
@@ -201,7 +201,7 @@
     uint64_t frameNumber = mQueueItems[0].mFrameNumber;
 
     // The head of the queue will be dropped if there are signaled and timely frames behind it
-    nsecs_t expectedPresentTime = mFlinger->mScheduler->expectedPresentTime();
+    nsecs_t expectedPresentTime = mFlinger->getExpectedPresentTime();
 
     if (isRemovedFromCurrentState()) {
         expectedPresentTime = 0;
@@ -279,7 +279,7 @@
                     getProducerStickyTransform() != 0, mName.string(), mOverrideScalingMode,
                     getTransformToDisplayInverse(), mFreezeGeometryUpdates);
 
-    nsecs_t expectedPresentTime = mFlinger->mScheduler->expectedPresentTime();
+    nsecs_t expectedPresentTime = mFlinger->getExpectedPresentTime();
 
     if (isRemovedFromCurrentState()) {
         expectedPresentTime = 0;
@@ -316,6 +316,7 @@
         // and return early
         if (queuedBuffer) {
             Mutex::Autolock lock(mQueueItemLock);
+            mConsumer->mergeSurfaceDamage(mQueueItems[0].mSurfaceDamage);
             mFlinger->mTimeStats->removeTimeRecord(layerID, mQueueItems[0].mFrameNumber);
             mQueueItems.removeAt(0);
             mQueuedFrames--;
@@ -351,6 +352,7 @@
         // Remove any stale buffers that have been dropped during
         // updateTexImage
         while (mQueueItems[0].mFrameNumber != currentFrameNumber) {
+            mConsumer->mergeSurfaceDamage(mQueueItems[0].mSurfaceDamage);
             mFlinger->mTimeStats->removeTimeRecord(layerID, mQueueItems[0].mFrameNumber);
             mQueueItems.removeAt(0);
             mQueuedFrames--;
diff --git a/services/surfaceflinger/BufferStateLayer.cpp b/services/surfaceflinger/BufferStateLayer.cpp
index 05c721f..63a07c3 100644
--- a/services/surfaceflinger/BufferStateLayer.cpp
+++ b/services/surfaceflinger/BufferStateLayer.cpp
@@ -50,8 +50,12 @@
     mOverrideScalingMode = NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW;
     mCurrentState.dataspace = ui::Dataspace::V0_SRGB;
 }
+
 BufferStateLayer::~BufferStateLayer() {
     if (mActiveBuffer != nullptr) {
+        // Ensure that mActiveBuffer is uncached from RenderEngine here, as
+        // RenderEngine may have been using the buffer as an external texture
+        // after the client uncached the buffer.
         auto& engine(mFlinger->getRenderEngine());
         engine.unbindExternalTextureBuffer(mActiveBuffer->getId());
     }
@@ -380,7 +384,7 @@
         return true;
     }
 
-    return mDesiredPresentTime <= mFlinger->mScheduler->expectedPresentTime();
+    return mDesiredPresentTime <= mFlinger->getExpectedPresentTime();
 }
 
 nsecs_t BufferStateLayer::getDesiredPresentTime() {
@@ -571,11 +575,6 @@
         return BAD_VALUE;
     }
 
-    if (mActiveBuffer != nullptr) {
-        // todo: get this to work with BufferStateLayerCache
-        auto& engine(mFlinger->getRenderEngine());
-        engine.unbindExternalTextureBuffer(mActiveBuffer->getId());
-    }
     mActiveBuffer = s.buffer;
     mActiveBufferFence = s.acquireFence;
     auto& layerCompositionState = getCompositionLayer()->editState().frontEnd;
diff --git a/services/surfaceflinger/BufferStateLayer.h b/services/surfaceflinger/BufferStateLayer.h
index 4e2bc45..97e24cb 100644
--- a/services/surfaceflinger/BufferStateLayer.h
+++ b/services/surfaceflinger/BufferStateLayer.h
@@ -34,6 +34,7 @@
 class BufferStateLayer : public BufferLayer {
 public:
     explicit BufferStateLayer(const LayerCreationArgs&);
+
     ~BufferStateLayer() override;
 
     // -----------------------------------------------------------------------
diff --git a/services/surfaceflinger/ClientCache.cpp b/services/surfaceflinger/ClientCache.cpp
index 77f2f57..16fe27c 100644
--- a/services/surfaceflinger/ClientCache.cpp
+++ b/services/surfaceflinger/ClientCache.cpp
@@ -55,16 +55,16 @@
     return true;
 }
 
-void ClientCache::add(const client_cache_t& cacheId, const sp<GraphicBuffer>& buffer) {
+bool ClientCache::add(const client_cache_t& cacheId, const sp<GraphicBuffer>& buffer) {
     auto& [processToken, id] = cacheId;
     if (processToken == nullptr) {
         ALOGE("failed to cache buffer: invalid process token");
-        return;
+        return false;
     }
 
     if (!buffer) {
         ALOGE("failed to cache buffer: invalid buffer");
-        return;
+        return false;
     }
 
     std::lock_guard lock(mMutex);
@@ -77,13 +77,13 @@
         token = processToken.promote();
         if (!token) {
             ALOGE("failed to cache buffer: invalid token");
-            return;
+            return false;
         }
 
         status_t err = token->linkToDeath(mDeathRecipient);
         if (err != NO_ERROR) {
             ALOGE("failed to cache buffer: could not link to death");
-            return;
+            return false;
         }
         auto [itr, success] =
                 mBuffers.emplace(processToken, std::unordered_map<uint64_t, ClientCacheBuffer>());
@@ -95,10 +95,11 @@
 
     if (processBuffers.size() > BUFFER_CACHE_MAX_SIZE) {
         ALOGE("failed to cache buffer: cache is full");
-        return;
+        return false;
     }
 
     processBuffers[id].buffer = buffer;
+    return true;
 }
 
 void ClientCache::erase(const client_cache_t& cacheId) {
@@ -139,16 +140,17 @@
     return buf->buffer;
 }
 
-void ClientCache::registerErasedRecipient(const client_cache_t& cacheId,
+bool ClientCache::registerErasedRecipient(const client_cache_t& cacheId,
                                           const wp<ErasedRecipient>& recipient) {
     std::lock_guard lock(mMutex);
 
     ClientCacheBuffer* buf = nullptr;
     if (!getBuffer(cacheId, &buf)) {
         ALOGE("failed to register erased recipient, could not retrieve buffer");
-        return;
+        return false;
     }
     buf->recipients.insert(recipient);
+    return true;
 }
 
 void ClientCache::unregisterErasedRecipient(const client_cache_t& cacheId,
diff --git a/services/surfaceflinger/ClientCache.h b/services/surfaceflinger/ClientCache.h
index 9f057c4..aa6c80d 100644
--- a/services/surfaceflinger/ClientCache.h
+++ b/services/surfaceflinger/ClientCache.h
@@ -36,7 +36,7 @@
 public:
     ClientCache();
 
-    void add(const client_cache_t& cacheId, const sp<GraphicBuffer>& buffer);
+    bool add(const client_cache_t& cacheId, const sp<GraphicBuffer>& buffer);
     void erase(const client_cache_t& cacheId);
 
     sp<GraphicBuffer> get(const client_cache_t& cacheId);
@@ -48,7 +48,7 @@
         virtual void bufferErased(const client_cache_t& clientCacheId) = 0;
     };
 
-    void registerErasedRecipient(const client_cache_t& cacheId,
+    bool registerErasedRecipient(const client_cache_t& cacheId,
                                  const wp<ErasedRecipient>& recipient);
     void unregisterErasedRecipient(const client_cache_t& cacheId,
                                    const wp<ErasedRecipient>& recipient);
diff --git a/services/surfaceflinger/DisplayHardware/ComposerHal.cpp b/services/surfaceflinger/DisplayHardware/ComposerHal.cpp
index cc5a5b5..7f47a2e 100644
--- a/services/surfaceflinger/DisplayHardware/ComposerHal.cpp
+++ b/services/surfaceflinger/DisplayHardware/ComposerHal.cpp
@@ -24,6 +24,7 @@
 
 #include <composer-command-buffer/2.2/ComposerCommandBuffer.h>
 #include <gui/BufferQueue.h>
+#include <hidl/HidlTransportSupport.h>
 #include <hidl/HidlTransportUtils.h>
 
 namespace android {
@@ -229,6 +230,7 @@
 
 void Composer::registerCallback(const sp<IComposerCallback>& callback)
 {
+    android::hardware::setMinSchedulerPolicy(callback, SCHED_FIFO, 2);
     auto ret = mClient->registerCallback(callback);
     if (!ret.isOk()) {
         ALOGE("failed to register IComposerCallback");
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 1318bc0..d6e86eb 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -2037,6 +2037,13 @@
     return mRemovedFromCurrentState;
 }
 
+// Debug helper for b/137560795
+#define INT32_MIGHT_OVERFLOW(n) (((n) >= INT32_MAX / 2) || ((n) <= INT32_MIN / 2))
+
+#define RECT_BOUNDS_INVALID(rect)                                               \
+    (INT32_MIGHT_OVERFLOW((rect).left) || INT32_MIGHT_OVERFLOW((rect).right) || \
+     INT32_MIGHT_OVERFLOW((rect).bottom) || INT32_MIGHT_OVERFLOW((rect).top))
+
 InputWindowInfo Layer::fillInputInfo() {
     InputWindowInfo info = mDrawingState.inputInfo;
 
@@ -2066,6 +2073,26 @@
         layerBounds = getCroppedBufferSize(getDrawingState());
     }
     layerBounds = t.transform(layerBounds);
+
+    // debug check for b/137560795
+    {
+        if (RECT_BOUNDS_INVALID(layerBounds)) {
+            ALOGE("layer %s bounds are invalid (%" PRIi32 ", %" PRIi32 ", %" PRIi32 ", %" PRIi32
+                  ")",
+                  mName.c_str(), layerBounds.left, layerBounds.top, layerBounds.right,
+                  layerBounds.bottom);
+            std::string out;
+            getTransform().dump(out, "Transform");
+            ALOGE("%s", out.c_str());
+            layerBounds.left = layerBounds.top = layerBounds.right = layerBounds.bottom = 0;
+        }
+
+        if (INT32_MIGHT_OVERFLOW(xSurfaceInset) || INT32_MIGHT_OVERFLOW(ySurfaceInset)) {
+            ALOGE("layer %s surface inset are invalid (%" PRIi32 ", %" PRIi32 ")", mName.c_str(),
+                  int32_t(xSurfaceInset), int32_t(ySurfaceInset));
+            xSurfaceInset = ySurfaceInset = 0;
+        }
+    }
     layerBounds.inset(xSurfaceInset, ySurfaceInset, xSurfaceInset, ySurfaceInset);
 
     // Input coordinate should match the layer bounds.
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 8a80e15..b46eb11 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -17,8 +17,6 @@
 #ifndef ANDROID_LAYER_H
 #define ANDROID_LAYER_H
 
-#include <sys/types.h>
-
 #include <compositionengine/LayerFE.h>
 #include <gui/BufferQueue.h>
 #include <gui/ISurfaceComposerClient.h>
@@ -28,6 +26,7 @@
 #include <math/vec4.h>
 #include <renderengine/Mesh.h>
 #include <renderengine/Texture.h>
+#include <sys/types.h>
 #include <ui/FloatRect.h>
 #include <ui/FrameStats.h>
 #include <ui/GraphicBuffer.h>
@@ -44,16 +43,16 @@
 #include <vector>
 
 #include "Client.h"
+#include "ClientCache.h"
+#include "DisplayHardware/ComposerHal.h"
+#include "DisplayHardware/HWComposer.h"
 #include "FrameTracker.h"
 #include "LayerVector.h"
 #include "MonitoredProducer.h"
+#include "RenderArea.h"
 #include "SurfaceFlinger.h"
 #include "TransactionCompletedThread.h"
 
-#include "DisplayHardware/ComposerHal.h"
-#include "DisplayHardware/HWComposer.h"
-#include "RenderArea.h"
-
 using namespace android::surfaceflinger;
 
 namespace android {
diff --git a/services/surfaceflinger/RegionSamplingThread.cpp b/services/surfaceflinger/RegionSamplingThread.cpp
index 66906e9..07fdead 100644
--- a/services/surfaceflinger/RegionSamplingThread.cpp
+++ b/services/surfaceflinger/RegionSamplingThread.cpp
@@ -44,11 +44,14 @@
 enum class samplingStep {
     noWorkNeeded,
     idleTimerWaiting,
+    waitForQuietFrame,
     waitForZeroPhase,
     waitForSamplePhase,
     sample
 };
 
+constexpr auto timeForRegionSampling = 5000000ns;
+constexpr auto maxRegionSamplingSkips = 10;
 constexpr auto defaultRegionSamplingOffset = -3ms;
 constexpr auto defaultRegionSamplingPeriod = 100ms;
 constexpr auto defaultRegionSamplingTimerTimeout = 100ms;
@@ -215,9 +218,9 @@
 void RegionSamplingThread::checkForStaleLuma() {
     std::lock_guard lock(mThreadControlMutex);
 
-    if (mDiscardedFrames) {
+    if (mDiscardedFrames > 0) {
         ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::waitForZeroPhase));
-        mDiscardedFrames = false;
+        mDiscardedFrames = 0;
         mPhaseCallback->startVsyncListener();
     }
 }
@@ -235,13 +238,25 @@
     auto now = std::chrono::nanoseconds(systemTime(SYSTEM_TIME_MONOTONIC));
     if (lastSampleTime + mTunables.mSamplingPeriod > now) {
         ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::idleTimerWaiting));
-        mDiscardedFrames = true;
+        if (mDiscardedFrames == 0) mDiscardedFrames++;
         return;
     }
+    if (mDiscardedFrames < maxRegionSamplingSkips) {
+        // If there is relatively little time left for surfaceflinger
+        // until the next vsync deadline, defer this sampling work
+        // to a later frame, when hopefully there will be more time.
+        DisplayStatInfo stats;
+        mScheduler.getDisplayStatInfo(&stats);
+        if (std::chrono::nanoseconds(stats.vsyncTime) - now < timeForRegionSampling) {
+            ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::waitForQuietFrame));
+            mDiscardedFrames++;
+            return;
+        }
+    }
 
     ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::sample));
 
-    mDiscardedFrames = false;
+    mDiscardedFrames = 0;
     lastSampleTime = now;
 
     mIdleTimer.reset();
@@ -258,7 +273,7 @@
 
 namespace {
 // Using Rec. 709 primaries
-float getLuma(float r, float g, float b) {
+inline float getLuma(float r, float g, float b) {
     constexpr auto rec709_red_primary = 0.2126f;
     constexpr auto rec709_green_primary = 0.7152f;
     constexpr auto rec709_blue_primary = 0.0722f;
@@ -293,10 +308,10 @@
         const uint32_t* rowBase = data + row * stride;
         for (int32_t column = area.left; column < area.right; ++column) {
             uint32_t pixel = rowBase[column];
-            const float r = (pixel & 0xFF) / 255.0f;
-            const float g = ((pixel >> 8) & 0xFF) / 255.0f;
-            const float b = ((pixel >> 16) & 0xFF) / 255.0f;
-            const uint8_t luma = std::round(getLuma(r, g, b) * 255.0f);
+            const float r = pixel & 0xFF;
+            const float g = (pixel >> 8) & 0xFF;
+            const float b = (pixel >> 16) & 0xFF;
+            const uint8_t luma = std::round(getLuma(r, g, b));
             ++brightnessBuckets[luma];
             if (brightnessBuckets[luma] > majoritySampleNum) return luma / 255.0f;
         }
@@ -342,9 +357,19 @@
     }
 
     const auto device = mFlinger.getDefaultDisplayDevice();
-    const auto display = device->getCompositionDisplay();
-    const auto state = display->getState();
-    const auto orientation = static_cast<ui::Transform::orientation_flags>(state.orientation);
+    const auto orientation = [](uint32_t orientation) {
+        switch (orientation) {
+            default:
+            case DisplayState::eOrientationDefault:
+                return ui::Transform::ROT_0;
+            case DisplayState::eOrientation90:
+                return ui::Transform::ROT_90;
+            case DisplayState::eOrientation180:
+                return ui::Transform::ROT_180;
+            case DisplayState::eOrientation270:
+                return ui::Transform::ROT_270;
+        }
+    }(device->getOrientation());
 
     std::vector<RegionSamplingThread::Descriptor> descriptors;
     Region sampleRegion;
diff --git a/services/surfaceflinger/RegionSamplingThread.h b/services/surfaceflinger/RegionSamplingThread.h
index 3c6fcf3..96ffe20 100644
--- a/services/surfaceflinger/RegionSamplingThread.h
+++ b/services/surfaceflinger/RegionSamplingThread.h
@@ -117,7 +117,7 @@
     std::condition_variable_any mCondition;
     bool mRunning GUARDED_BY(mThreadControlMutex) = true;
     bool mSampleRequested GUARDED_BY(mThreadControlMutex) = false;
-    bool mDiscardedFrames GUARDED_BY(mThreadControlMutex) = false;
+    uint32_t mDiscardedFrames GUARDED_BY(mThreadControlMutex) = 0;
     std::chrono::nanoseconds lastSampleTime GUARDED_BY(mThreadControlMutex);
 
     std::mutex mSamplingMutex;
diff --git a/services/surfaceflinger/Scheduler/DispSync.cpp b/services/surfaceflinger/Scheduler/DispSync.cpp
index cd6fa41..0c94052 100644
--- a/services/surfaceflinger/Scheduler/DispSync.cpp
+++ b/services/surfaceflinger/Scheduler/DispSync.cpp
@@ -79,11 +79,7 @@
         Mutex::Autolock lock(mMutex);
 
         mPhase = phase;
-        if (mReferenceTime != referenceTime) {
-            for (auto& eventListener : mEventListeners) {
-                eventListener.mHasFired = false;
-            }
-        }
+        const bool referenceTimeChanged = mReferenceTime != referenceTime;
         mReferenceTime = referenceTime;
         if (mPeriod != 0 && mPeriod != period && mReferenceTime != 0) {
             // Inflate the reference time to be the most recent predicted
@@ -94,6 +90,16 @@
             mReferenceTime = mReferenceTime + (numOldPeriods)*mPeriod;
         }
         mPeriod = period;
+        if (!mModelLocked && referenceTimeChanged) {
+            for (auto& eventListener : mEventListeners) {
+                eventListener.mLastEventTime = mReferenceTime + mPhase + eventListener.mPhase;
+                // If mLastEventTime is after mReferenceTime (can happen when positive phase offsets
+                // are used) we treat it as like it happened in previous period.
+                if (eventListener.mLastEventTime > mReferenceTime) {
+                    eventListener.mLastEventTime -= mPeriod;
+                }
+            }
+        }
         if (mTraceDetailedInfo) {
             ATRACE_INT64("DispSync:Period", mPeriod);
             ATRACE_INT64("DispSync:Phase", mPhase + mPeriod / 2);
@@ -115,11 +121,13 @@
     void lockModel() {
         Mutex::Autolock lock(mMutex);
         mModelLocked = true;
+        ATRACE_INT("DispSync:ModelLocked", mModelLocked);
     }
 
     void unlockModel() {
         Mutex::Autolock lock(mMutex);
         mModelLocked = false;
+        ATRACE_INT("DispSync:ModelLocked", mModelLocked);
     }
 
     virtual bool threadLoop() {
@@ -284,12 +292,8 @@
                 // new offset to allow for a seamless offset change without double-firing or
                 // skipping.
                 nsecs_t diff = oldPhase - phase;
-                if (diff > mPeriod / 2) {
-                    diff -= mPeriod;
-                } else if (diff < -mPeriod / 2) {
-                    diff += mPeriod;
-                }
                 eventListener.mLastEventTime -= diff;
+                eventListener.mLastCallbackTime -= diff;
                 mCond.signal();
                 return NO_ERROR;
             }
@@ -304,7 +308,6 @@
         nsecs_t mLastEventTime;
         nsecs_t mLastCallbackTime;
         DispSync::Callback* mCallback;
-        bool mHasFired = false;
     };
 
     struct CallbackInvocation {
@@ -352,12 +355,7 @@
                           eventListener.mName);
                     continue;
                 }
-                if (eventListener.mHasFired && !mModelLocked) {
-                    eventListener.mLastEventTime = t;
-                    ALOGV("[%s] [%s] Skipping event due to already firing", mName,
-                          eventListener.mName);
-                    continue;
-                }
+
                 CallbackInvocation ci;
                 ci.mCallback = eventListener.mCallback;
                 ci.mEventTime = t;
@@ -366,7 +364,6 @@
                 callbackInvocations.push_back(ci);
                 eventListener.mLastEventTime = t;
                 eventListener.mLastCallbackTime = now;
-                eventListener.mHasFired = true;
             }
         }
 
@@ -493,7 +490,6 @@
         ALOGE("Couldn't set SCHED_FIFO for DispSyncThread");
     }
 
-    reset();
     beginResync();
 
     if (mTraceDetailedInfo && kEnableZeroPhaseTracer) {
@@ -545,17 +541,15 @@
 void DispSync::beginResync() {
     Mutex::Autolock lock(mMutex);
     ALOGV("[%s] beginResync", mName);
-    mThread->unlockModel();
-    mModelUpdated = false;
-    mNumResyncSamples = 0;
+    resetLocked();
 }
 
-bool DispSync::addResyncSample(nsecs_t timestamp, bool* periodChanged) {
+bool DispSync::addResyncSample(nsecs_t timestamp, bool* periodFlushed) {
     Mutex::Autolock lock(mMutex);
 
     ALOGV("[%s] addResyncSample(%" PRId64 ")", mName, ns2us(timestamp));
 
-    *periodChanged = false;
+    *periodFlushed = false;
     const size_t idx = (mFirstResyncSample + mNumResyncSamples) % MAX_RESYNC_SAMPLES;
     mResyncSamples[idx] = timestamp;
     if (mNumResyncSamples == 0) {
@@ -569,16 +563,20 @@
         const nsecs_t lastTimestamp = mResyncSamples[priorIdx];
 
         const nsecs_t observedVsync = std::abs(timestamp - lastTimestamp);
-        if (std::abs(observedVsync - mPendingPeriod) < std::abs(observedVsync - mPeriod)) {
-            // Observed vsync is closer to the pending period, so reset the
-            // model and flush the pending period.
+        if (std::abs(observedVsync - mPendingPeriod) <= std::abs(observedVsync - mIntendedPeriod)) {
+            // Either the observed vsync is closer to the pending period, (and
+            // thus we detected a period change), or the period change will
+            // no-op. In either case, reset the model and flush the pending
+            // period.
             resetLocked();
+            mIntendedPeriod = mPendingPeriod;
             mPeriod = mPendingPeriod;
             mPendingPeriod = 0;
             if (mTraceDetailedInfo) {
                 ATRACE_INT("DispSync:PendingPeriod", mPendingPeriod);
+                ATRACE_INT("DispSync:IntendedPeriod", mIntendedPeriod);
             }
-            *periodChanged = true;
+            *periodFlushed = true;
         }
     }
     // Always update the reference time with the most recent timestamp.
@@ -609,6 +607,7 @@
     bool modelLocked = mModelUpdated && mError < (kErrorThreshold / 2) && mPendingPeriod == 0;
     ALOGV("[%s] addResyncSample returning %s", mName, modelLocked ? "locked" : "unlocked");
     if (modelLocked) {
+        *periodFlushed = true;
         mThread->lockModel();
     }
     return !modelLocked;
@@ -643,10 +642,17 @@
 
 void DispSync::setPeriod(nsecs_t period) {
     Mutex::Autolock lock(mMutex);
-    if (mTraceDetailedInfo) {
-        ATRACE_INT("DispSync:PendingPeriod", period);
+
+    const bool pendingPeriodShouldChange =
+            period != mIntendedPeriod || (period == mIntendedPeriod && mPendingPeriod != 0);
+
+    if (pendingPeriodShouldChange) {
+        mPendingPeriod = period;
     }
-    mPendingPeriod = period;
+    if (mTraceDetailedInfo) {
+        ATRACE_INT("DispSync:IntendedPeriod", mIntendedPeriod);
+        ATRACE_INT("DispSync:PendingPeriod", mPendingPeriod);
+    }
 }
 
 nsecs_t DispSync::getPeriod() {
@@ -662,7 +668,13 @@
         nsecs_t durationSum = 0;
         nsecs_t minDuration = INT64_MAX;
         nsecs_t maxDuration = 0;
-        for (size_t i = 1; i < mNumResyncSamples; i++) {
+        // We skip the first 2 samples because the first vsync duration on some
+        // devices may be much more inaccurate than on other devices, e.g. due
+        // to delays in ramping up from a power collapse. By doing so this
+        // actually increases the accuracy of the DispSync model even though
+        // we're effectively relying on fewer sample points.
+        static constexpr size_t numSamplesSkipped = 2;
+        for (size_t i = numSamplesSkipped; i < mNumResyncSamples; i++) {
             size_t idx = (mFirstResyncSample + i) % MAX_RESYNC_SAMPLES;
             size_t prev = (idx + MAX_RESYNC_SAMPLES - 1) % MAX_RESYNC_SAMPLES;
             nsecs_t duration = mResyncSamples[idx] - mResyncSamples[prev];
@@ -673,15 +685,14 @@
 
         // Exclude the min and max from the average
         durationSum -= minDuration + maxDuration;
-        mPeriod = durationSum / (mNumResyncSamples - 3);
+        mPeriod = durationSum / (mNumResyncSamples - numSamplesSkipped - 2);
 
         ALOGV("[%s] mPeriod = %" PRId64, mName, ns2us(mPeriod));
 
         double sampleAvgX = 0;
         double sampleAvgY = 0;
         double scale = 2.0 * M_PI / double(mPeriod);
-        // Intentionally skip the first sample
-        for (size_t i = 1; i < mNumResyncSamples; i++) {
+        for (size_t i = numSamplesSkipped; i < mNumResyncSamples; i++) {
             size_t idx = (mFirstResyncSample + i) % MAX_RESYNC_SAMPLES;
             nsecs_t sample = mResyncSamples[idx] - mReferenceTime;
             double samplePhase = double(sample % mPeriod) * scale;
@@ -689,8 +700,8 @@
             sampleAvgY += sin(samplePhase);
         }
 
-        sampleAvgX /= double(mNumResyncSamples - 1);
-        sampleAvgY /= double(mNumResyncSamples - 1);
+        sampleAvgX /= double(mNumResyncSamples - numSamplesSkipped);
+        sampleAvgY /= double(mNumResyncSamples - numSamplesSkipped);
 
         mPhase = nsecs_t(atan2(sampleAvgY, sampleAvgX) / scale);
 
@@ -764,6 +775,9 @@
     mPresentSampleOffset = 0;
     mError = 0;
     mZeroErrSamplesCount = 0;
+    if (mTraceDetailedInfo) {
+        ATRACE_INT64("DispSync:Error", mError);
+    }
     for (size_t i = 0; i < NUM_PRESENT_SAMPLES; i++) {
         mPresentFences[i] = FenceTime::NO_FENCE;
     }
diff --git a/services/surfaceflinger/Scheduler/DispSync.h b/services/surfaceflinger/Scheduler/DispSync.h
index 8f8b8e7..3e33c7e 100644
--- a/services/surfaceflinger/Scheduler/DispSync.h
+++ b/services/surfaceflinger/Scheduler/DispSync.h
@@ -49,7 +49,7 @@
     virtual void reset() = 0;
     virtual bool addPresentFence(const std::shared_ptr<FenceTime>&) = 0;
     virtual void beginResync() = 0;
-    virtual bool addResyncSample(nsecs_t timestamp, bool* periodChanged) = 0;
+    virtual bool addResyncSample(nsecs_t timestamp, bool* periodFlushed) = 0;
     virtual void endResync() = 0;
     virtual void setPeriod(nsecs_t period) = 0;
     virtual nsecs_t getPeriod() = 0;
@@ -120,17 +120,19 @@
     // from the hardware vsync events.
     void beginResync() override;
     // Adds a vsync sample to the dispsync model. The timestamp is the time
-    // of the vsync event that fired. periodChanged will return true if the
+    // of the vsync event that fired. periodFlushed will return true if the
     // vsync period was detected to have changed to mPendingPeriod.
     //
     // This method will return true if more vsync samples are needed to lock
     // down the DispSync model, and false otherwise.
-    bool addResyncSample(nsecs_t timestamp, bool* periodChanged) override;
+    // periodFlushed will be set to true if mPendingPeriod is flushed to
+    // mIntendedPeriod, and false otherwise.
+    bool addResyncSample(nsecs_t timestamp, bool* periodFlushed) override;
     void endResync() override;
 
     // The setPeriod method sets the vsync event model's period to a specific
-    // value.  This should be used to prime the model when a display is first
-    // turned on.  It should NOT be used after that.
+    // value. This should be used to prime the model when a display is first
+    // turned on, or when a refresh rate change is requested.
     void setPeriod(nsecs_t period) override;
 
     // The getPeriod method returns the current vsync period.
@@ -205,6 +207,11 @@
     // nanoseconds.
     nsecs_t mPeriod;
 
+    // mIntendedPeriod is the intended period of the modeled vsync events in
+    // nanoseconds. Under ideal conditions this should be similar if not the
+    // same as mPeriod, plus or minus an observed error.
+    nsecs_t mIntendedPeriod = 0;
+
     // mPendingPeriod is the proposed period change in nanoseconds.
     // If mPendingPeriod differs from mPeriod and is nonzero, it will
     // be flushed to mPeriod when we detect that the hardware switched
@@ -236,8 +243,8 @@
     // process to store information about the hardware vsync event times used
     // to compute the model.
     nsecs_t mResyncSamples[MAX_RESYNC_SAMPLES] = {0};
-    size_t mFirstResyncSample;
-    size_t mNumResyncSamples;
+    size_t mFirstResyncSample = 0;
+    size_t mNumResyncSamples = 0;
     int mNumResyncSamplesSincePresent;
 
     // These member variables store information about the present fences used
diff --git a/services/surfaceflinger/Scheduler/DispSyncSource.cpp b/services/surfaceflinger/Scheduler/DispSyncSource.cpp
index 00948ae..5faf46e 100644
--- a/services/surfaceflinger/Scheduler/DispSyncSource.cpp
+++ b/services/surfaceflinger/Scheduler/DispSyncSource.cpp
@@ -27,18 +27,23 @@
 
 namespace android {
 
-DispSyncSource::DispSyncSource(DispSync* dispSync, nsecs_t phaseOffset, bool traceVsync,
+DispSyncSource::DispSyncSource(DispSync* dispSync, nsecs_t phaseOffset,
+                               nsecs_t offsetThresholdForNextVsync, bool traceVsync,
                                const char* name)
       : mName(name),
         mTraceVsync(traceVsync),
         mVsyncOnLabel(base::StringPrintf("VsyncOn-%s", name)),
         mVsyncEventLabel(base::StringPrintf("VSYNC-%s", name)),
+        mVsyncOffsetLabel(base::StringPrintf("VsyncOffset-%s", name)),
+        mVsyncNegativeOffsetLabel(base::StringPrintf("VsyncNegativeOffset-%s", name)),
         mDispSync(dispSync),
-        mPhaseOffset(phaseOffset) {}
+        mPhaseOffset(phaseOffset),
+        mOffsetThresholdForNextVsync(offsetThresholdForNextVsync) {}
 
 void DispSyncSource::setVSyncEnabled(bool enable) {
     std::lock_guard lock(mVsyncMutex);
     if (enable) {
+        tracePhaseOffset();
         status_t err = mDispSync->addEventListener(mName, mPhaseOffset,
                                                    static_cast<DispSync::Callback*>(this),
                                                    mLastCallbackTime);
@@ -64,16 +69,21 @@
 
 void DispSyncSource::setPhaseOffset(nsecs_t phaseOffset) {
     std::lock_guard lock(mVsyncMutex);
-
-    // Normalize phaseOffset to [0, period)
-    auto period = mDispSync->getPeriod();
-    phaseOffset %= period;
-    if (phaseOffset < 0) {
-        // If we're here, then phaseOffset is in (-period, 0). After this
-        // operation, it will be in (0, period)
-        phaseOffset += period;
+    const nsecs_t period = mDispSync->getPeriod();
+    // Check if offset should be handled as negative
+    if (phaseOffset >= mOffsetThresholdForNextVsync) {
+        phaseOffset -= period;
     }
+
+    // Normalize phaseOffset to [-period, period)
+    const int numPeriods = phaseOffset / period;
+    phaseOffset -= numPeriods * period;
+    if (mPhaseOffset == phaseOffset) {
+        return;
+    }
+
     mPhaseOffset = phaseOffset;
+    tracePhaseOffset();
 
     // If we're not enabled, we don't need to mess with the listeners
     if (!mEnabled) {
@@ -92,11 +102,11 @@
     {
         std::lock_guard lock(mCallbackMutex);
         callback = mCallback;
+    }
 
-        if (mTraceVsync) {
-            mValue = (mValue + 1) % 2;
-            ATRACE_INT(mVsyncEventLabel.c_str(), mValue);
-        }
+    if (mTraceVsync) {
+        mValue = (mValue + 1) % 2;
+        ATRACE_INT(mVsyncEventLabel.c_str(), mValue);
     }
 
     if (callback != nullptr) {
@@ -104,4 +114,14 @@
     }
 }
 
-} // namespace android
\ No newline at end of file
+void DispSyncSource::tracePhaseOffset() {
+    if (mPhaseOffset > 0) {
+        ATRACE_INT(mVsyncOffsetLabel.c_str(), mPhaseOffset);
+        ATRACE_INT(mVsyncNegativeOffsetLabel.c_str(), 0);
+    } else {
+        ATRACE_INT(mVsyncOffsetLabel.c_str(), 0);
+        ATRACE_INT(mVsyncNegativeOffsetLabel.c_str(), -mPhaseOffset);
+    }
+}
+
+} // namespace android
diff --git a/services/surfaceflinger/Scheduler/DispSyncSource.h b/services/surfaceflinger/Scheduler/DispSyncSource.h
index 4759699..50560a5 100644
--- a/services/surfaceflinger/Scheduler/DispSyncSource.h
+++ b/services/surfaceflinger/Scheduler/DispSyncSource.h
@@ -25,7 +25,8 @@
 
 class DispSyncSource final : public VSyncSource, private DispSync::Callback {
 public:
-    DispSyncSource(DispSync* dispSync, nsecs_t phaseOffset, bool traceVsync, const char* name);
+    DispSyncSource(DispSync* dispSync, nsecs_t phaseOffset, nsecs_t offsetThresholdForNextVsync,
+                   bool traceVsync, const char* name);
 
     ~DispSyncSource() override = default;
 
@@ -38,12 +39,16 @@
     // The following method is the implementation of the DispSync::Callback.
     virtual void onDispSyncEvent(nsecs_t when);
 
+    void tracePhaseOffset() REQUIRES(mVsyncMutex);
+
     const char* const mName;
     int mValue = 0;
 
     const bool mTraceVsync;
     const std::string mVsyncOnLabel;
     const std::string mVsyncEventLabel;
+    const std::string mVsyncOffsetLabel;
+    const std::string mVsyncNegativeOffsetLabel;
     nsecs_t mLastCallbackTime GUARDED_BY(mVsyncMutex) = 0;
 
     DispSync* mDispSync;
@@ -53,7 +58,8 @@
 
     std::mutex mVsyncMutex;
     nsecs_t mPhaseOffset GUARDED_BY(mVsyncMutex);
+    const nsecs_t mOffsetThresholdForNextVsync;
     bool mEnabled GUARDED_BY(mVsyncMutex) = false;
 };
 
-} // namespace android
\ No newline at end of file
+} // namespace android
diff --git a/services/surfaceflinger/Scheduler/EventThread.cpp b/services/surfaceflinger/Scheduler/EventThread.cpp
index 05bad4d..9d1f777 100644
--- a/services/surfaceflinger/Scheduler/EventThread.cpp
+++ b/services/surfaceflinger/Scheduler/EventThread.cpp
@@ -76,6 +76,10 @@
             return StringPrintf("VSync{displayId=%" ANDROID_PHYSICAL_DISPLAY_ID_FORMAT
                                 ", count=%u}",
                                 event.header.displayId, event.vsync.count);
+        case DisplayEventReceiver::DISPLAY_EVENT_CONFIG_CHANGED:
+            return StringPrintf("ConfigChanged{displayId=%" ANDROID_PHYSICAL_DISPLAY_ID_FORMAT
+                                ", configId=%u}",
+                                event.header.displayId, event.config.configId);
         default:
             return "Event{}";
     }
@@ -107,8 +111,10 @@
 } // namespace
 
 EventThreadConnection::EventThreadConnection(EventThread* eventThread,
-                                             ResyncCallback resyncCallback)
+                                             ResyncCallback resyncCallback,
+                                             ISurfaceComposer::ConfigChanged configChanged)
       : resyncCallback(std::move(resyncCallback)),
+        configChanged(configChanged),
         mEventThread(eventThread),
         mChannel(gui::BitTube::DefaultSize) {}
 
@@ -203,8 +209,10 @@
     mVSyncSource->setPhaseOffset(phaseOffset);
 }
 
-sp<EventThreadConnection> EventThread::createEventConnection(ResyncCallback resyncCallback) const {
-    return new EventThreadConnection(const_cast<EventThread*>(this), std::move(resyncCallback));
+sp<EventThreadConnection> EventThread::createEventConnection(
+        ResyncCallback resyncCallback, ISurfaceComposer::ConfigChanged configChanged) const {
+    return new EventThreadConnection(const_cast<EventThread*>(this), std::move(resyncCallback),
+                                     configChanged);
 }
 
 status_t EventThread::registerDisplayEventConnection(const sp<EventThreadConnection>& connection) {
@@ -398,9 +406,11 @@
                                      const sp<EventThreadConnection>& connection) const {
     switch (event.header.type) {
         case DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG:
-        case DisplayEventReceiver::DISPLAY_EVENT_CONFIG_CHANGED:
             return true;
 
+        case DisplayEventReceiver::DISPLAY_EVENT_CONFIG_CHANGED:
+            return connection->configChanged == ISurfaceComposer::eConfigChangedDispatch;
+
         case DisplayEventReceiver::DISPLAY_EVENT_VSYNC:
             switch (connection->vsyncRequest) {
                 case VSyncRequest::None:
diff --git a/services/surfaceflinger/Scheduler/EventThread.h b/services/surfaceflinger/Scheduler/EventThread.h
index 61530c6..dd23b88 100644
--- a/services/surfaceflinger/Scheduler/EventThread.h
+++ b/services/surfaceflinger/Scheduler/EventThread.h
@@ -69,7 +69,8 @@
 
 class EventThreadConnection : public BnDisplayEventConnection {
 public:
-    EventThreadConnection(EventThread*, ResyncCallback);
+    EventThreadConnection(EventThread*, ResyncCallback,
+                          ISurfaceComposer::ConfigChanged configChanged);
     virtual ~EventThreadConnection();
 
     virtual status_t postEvent(const DisplayEventReceiver::Event& event);
@@ -82,6 +83,7 @@
     const ResyncCallback resyncCallback;
 
     VSyncRequest vsyncRequest = VSyncRequest::None;
+    const ISurfaceComposer::ConfigChanged configChanged;
 
 private:
     virtual void onFirstRef();
@@ -93,7 +95,8 @@
 public:
     virtual ~EventThread();
 
-    virtual sp<EventThreadConnection> createEventConnection(ResyncCallback) const = 0;
+    virtual sp<EventThreadConnection> createEventConnection(
+            ResyncCallback, ISurfaceComposer::ConfigChanged configChanged) const = 0;
 
     // called before the screen is turned off from main thread
     virtual void onScreenReleased() = 0;
@@ -128,7 +131,8 @@
     EventThread(std::unique_ptr<VSyncSource>, InterceptVSyncsCallback, const char* threadName);
     ~EventThread();
 
-    sp<EventThreadConnection> createEventConnection(ResyncCallback) const override;
+    sp<EventThreadConnection> createEventConnection(
+            ResyncCallback, ISurfaceComposer::ConfigChanged configChanged) const override;
 
     status_t registerDisplayEventConnection(const sp<EventThreadConnection>& connection) override;
     void setVsyncRate(uint32_t rate, const sp<EventThreadConnection>& connection) override;
diff --git a/services/surfaceflinger/Scheduler/LayerHistory.cpp b/services/surfaceflinger/Scheduler/LayerHistory.cpp
index 1db43a3..f80c233 100644
--- a/services/surfaceflinger/Scheduler/LayerHistory.cpp
+++ b/services/surfaceflinger/Scheduler/LayerHistory.cpp
@@ -46,11 +46,13 @@
 LayerHistory::~LayerHistory() = default;
 
 std::unique_ptr<LayerHistory::LayerHandle> LayerHistory::createLayer(const std::string name,
+                                                                     float minRefreshRate,
                                                                      float maxRefreshRate) {
     const int64_t id = sNextId++;
 
     std::lock_guard lock(mLock);
-    mInactiveLayerInfos.emplace(id, std::make_shared<LayerInfo>(name, maxRefreshRate));
+    mInactiveLayerInfos.emplace(id,
+                                std::make_shared<LayerInfo>(name, minRefreshRate, maxRefreshRate));
     return std::make_unique<LayerHistory::LayerHandle>(*this, id);
 }
 
@@ -173,5 +175,18 @@
     }
 }
 
+void LayerHistory::clearHistory() {
+    std::lock_guard lock(mLock);
+
+    auto it = mActiveLayerInfos.begin();
+    while (it != mActiveLayerInfos.end()) {
+        auto id = it->first;
+        auto layerInfo = it->second;
+        layerInfo->clearHistory();
+        mInactiveLayerInfos.insert({id, layerInfo});
+        it = mActiveLayerInfos.erase(it);
+    }
+}
+
 } // namespace scheduler
 } // namespace android
\ No newline at end of file
diff --git a/services/surfaceflinger/Scheduler/LayerHistory.h b/services/surfaceflinger/Scheduler/LayerHistory.h
index adc5ce5..5598cc1 100644
--- a/services/surfaceflinger/Scheduler/LayerHistory.h
+++ b/services/surfaceflinger/Scheduler/LayerHistory.h
@@ -53,7 +53,8 @@
     ~LayerHistory();
 
     // When the layer is first created, register it.
-    std::unique_ptr<LayerHandle> createLayer(const std::string name, float maxRefreshRate);
+    std::unique_ptr<LayerHandle> createLayer(const std::string name, float minRefreshRate,
+                                             float maxRefreshRate);
 
     // Method for inserting layers and their requested present time into the unordered map.
     void insert(const std::unique_ptr<LayerHandle>& layerHandle, nsecs_t presentTime, bool isHdr);
@@ -64,6 +65,9 @@
     // layers. See go/content-fps-detection-in-scheduler for more information.
     std::pair<float, bool> getDesiredRefreshRateAndHDR();
 
+    // Clears all layer history.
+    void clearHistory();
+
     // Removes the handle and the object from the map.
     void destroyLayer(const int64_t id);
 
diff --git a/services/surfaceflinger/Scheduler/LayerInfo.cpp b/services/surfaceflinger/Scheduler/LayerInfo.cpp
index 95d7d31..723d71f 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.cpp
+++ b/services/surfaceflinger/Scheduler/LayerInfo.cpp
@@ -24,9 +24,10 @@
 namespace android {
 namespace scheduler {
 
-LayerInfo::LayerInfo(const std::string name, float maxRefreshRate)
+LayerInfo::LayerInfo(const std::string name, float minRefreshRate, float maxRefreshRate)
       : mName(name),
         mMinRefreshDuration(1e9f / maxRefreshRate),
+        mLowActivityRefreshDuration(1e9f / minRefreshRate),
         mRefreshRateHistory(mMinRefreshDuration) {}
 
 LayerInfo::~LayerInfo() = default;
@@ -38,12 +39,19 @@
     mLastUpdatedTime = std::max(lastPresentTime, systemTime());
     mPresentTimeHistory.insertPresentTime(mLastUpdatedTime);
 
+    if (mLastPresentTime == 0) {
+        // First frame
+        mLastPresentTime = lastPresentTime;
+        return;
+    }
+
     const nsecs_t timeDiff = lastPresentTime - mLastPresentTime;
     mLastPresentTime = lastPresentTime;
     // Ignore time diff that are too high - those are stale values
-    if (timeDiff > TIME_EPSILON_NS.count()) return;
-    const nsecs_t refreshDuration = (timeDiff > 0) ? timeDiff : mMinRefreshDuration;
-    mRefreshRateHistory.insertRefreshRate(refreshDuration);
+    if (timeDiff > OBSOLETE_TIME_EPSILON_NS.count()) return;
+    const nsecs_t refreshDuration = std::max(timeDiff, mMinRefreshDuration);
+    const int fps = 1e9f / refreshDuration;
+    mRefreshRateHistory.insertRefreshRate(fps);
 }
 
 } // namespace scheduler
diff --git a/services/surfaceflinger/Scheduler/LayerInfo.h b/services/surfaceflinger/Scheduler/LayerInfo.h
index 02b6aef..a733781 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.h
+++ b/services/surfaceflinger/Scheduler/LayerInfo.h
@@ -46,7 +46,7 @@
     public:
         explicit RefreshRateHistory(nsecs_t minRefreshDuration)
               : mMinRefreshDuration(minRefreshDuration) {}
-        void insertRefreshRate(nsecs_t refreshRate) {
+        void insertRefreshRate(int refreshRate) {
             mElements.push_back(refreshRate);
             if (mElements.size() > HISTORY_SIZE) {
                 mElements.pop_front();
@@ -54,13 +54,13 @@
         }
 
         float getRefreshRateAvg() const {
-            nsecs_t refreshDuration = mMinRefreshDuration;
-            if (mElements.size() == HISTORY_SIZE) {
-                refreshDuration = scheduler::calculate_mean(mElements);
+            if (mElements.empty()) {
+                return 1e9f / mMinRefreshDuration;
             }
 
-            return 1e9f / refreshDuration;
+            return scheduler::calculate_mean(mElements);
         }
+
         void clearHistory() { mElements.clear(); }
 
     private:
@@ -86,13 +86,42 @@
         // Checks whether the present time that was inserted HISTORY_SIZE ago is within a
         // certain threshold: TIME_EPSILON_NS.
         bool isRelevant() const {
-            const int64_t obsoleteEpsilon = systemTime() - scheduler::TIME_EPSILON_NS.count();
-            // The layer had to publish at least HISTORY_SIZE of updates, and the first
-            // update should not be older than TIME_EPSILON_NS nanoseconds.
-            if (mElements.size() == HISTORY_SIZE &&
-                mElements.at(HISTORY_SIZE - 1) > obsoleteEpsilon) {
+            if (mElements.size() < 2) {
+                return false;
+            }
+
+            // The layer had to publish at least HISTORY_SIZE or HISTORY_TIME of updates
+            if (mElements.size() != HISTORY_SIZE &&
+                mElements.at(mElements.size() - 1) - mElements.at(0) < HISTORY_TIME.count()) {
+                return false;
+            }
+
+            // The last update should not be older than OBSOLETE_TIME_EPSILON_NS nanoseconds.
+            const int64_t obsoleteEpsilon =
+                    systemTime() - scheduler::OBSOLETE_TIME_EPSILON_NS.count();
+            if (mElements.at(mElements.size() - 1) < obsoleteEpsilon) {
+                return false;
+            }
+
+            return true;
+        }
+
+        bool isLowActivityLayer() const {
+            // We want to make sure that we received more than two frames from the layer
+            // in order to check low activity.
+            if (mElements.size() < 2) {
+                return false;
+            }
+
+            const int64_t obsoleteEpsilon =
+                    systemTime() - scheduler::LOW_ACTIVITY_EPSILON_NS.count();
+            // Check the frame before last to determine whether there is low activity.
+            // If that frame is older than LOW_ACTIVITY_EPSILON_NS, the layer is sending
+            // infrequent updates.
+            if (mElements.at(mElements.size() - 2) < obsoleteEpsilon) {
                 return true;
             }
+
             return false;
         }
 
@@ -100,11 +129,12 @@
 
     private:
         std::deque<nsecs_t> mElements;
-        static constexpr size_t HISTORY_SIZE = 10;
+        static constexpr size_t HISTORY_SIZE = 90;
+        static constexpr std::chrono::nanoseconds HISTORY_TIME = 1s;
     };
 
 public:
-    LayerInfo(const std::string name, float maxRefreshRate);
+    LayerInfo(const std::string name, float minRefreshRate, float maxRefreshRate);
     ~LayerInfo();
 
     LayerInfo(const LayerInfo&) = delete;
@@ -134,6 +164,10 @@
     // Calculate the average refresh rate.
     float getDesiredRefreshRate() const {
         std::lock_guard lock(mLock);
+
+        if (mPresentTimeHistory.isLowActivityLayer()) {
+            return 1e9f / mLowActivityRefreshDuration;
+        }
         return mRefreshRateHistory.getRefreshRateAvg();
     }
 
@@ -165,6 +199,7 @@
 private:
     const std::string mName;
     const nsecs_t mMinRefreshDuration;
+    const nsecs_t mLowActivityRefreshDuration;
     mutable std::mutex mLock;
     nsecs_t mLastUpdatedTime GUARDED_BY(mLock) = 0;
     nsecs_t mLastPresentTime GUARDED_BY(mLock) = 0;
diff --git a/services/surfaceflinger/Scheduler/MessageQueue.cpp b/services/surfaceflinger/Scheduler/MessageQueue.cpp
index baf900d..fcb307f 100644
--- a/services/surfaceflinger/Scheduler/MessageQueue.cpp
+++ b/services/surfaceflinger/Scheduler/MessageQueue.cpp
@@ -96,7 +96,8 @@
     }
 
     mEventThread = eventThread;
-    mEvents = eventThread->createEventConnection(std::move(resyncCallback));
+    mEvents = eventThread->createEventConnection(std::move(resyncCallback),
+                                                 ISurfaceComposer::eConfigChangedSuppress);
     mEvents->stealReceiveChannel(&mEventTube);
     mLooper->addFd(mEventTube.getFd(), 0, Looper::EVENT_INPUT, MessageQueue::cb_eventReceiver,
                    this);
diff --git a/services/surfaceflinger/Scheduler/PhaseOffsets.cpp b/services/surfaceflinger/Scheduler/PhaseOffsets.cpp
index 276bce1..8a2604f 100644
--- a/services/surfaceflinger/Scheduler/PhaseOffsets.cpp
+++ b/services/surfaceflinger/Scheduler/PhaseOffsets.cpp
@@ -25,6 +25,7 @@
 
 namespace scheduler {
 
+using RefreshRateType = RefreshRateConfigs::RefreshRateType;
 PhaseOffsets::~PhaseOffsets() = default;
 
 namespace impl {
@@ -72,25 +73,32 @@
     property_get("debug.sf.phase_offset_threshold_for_next_vsync_ns", value, "-1");
     const int phaseOffsetThresholdForNextVsyncNs = atoi(value);
 
-    mDefaultRefreshRateOffsets.early = {earlySfOffsetNs != -1 ? earlySfOffsetNs
-                                                              : sfVsyncPhaseOffsetNs,
-                                        earlyAppOffsetNs != -1 ? earlyAppOffsetNs
-                                                               : vsyncPhaseOffsetNs};
-    mDefaultRefreshRateOffsets.earlyGl = {earlyGlSfOffsetNs != -1 ? earlyGlSfOffsetNs
-                                                                  : sfVsyncPhaseOffsetNs,
-                                          earlyGlAppOffsetNs != -1 ? earlyGlAppOffsetNs
-                                                                   : vsyncPhaseOffsetNs};
-    mDefaultRefreshRateOffsets.late = {sfVsyncPhaseOffsetNs, vsyncPhaseOffsetNs};
+    Offsets defaultOffsets;
+    Offsets highFpsOffsets;
+    defaultOffsets.early = {RefreshRateType::DEFAULT,
+                            earlySfOffsetNs != -1 ? earlySfOffsetNs : sfVsyncPhaseOffsetNs,
+                            earlyAppOffsetNs != -1 ? earlyAppOffsetNs : vsyncPhaseOffsetNs};
+    defaultOffsets.earlyGl = {RefreshRateType::DEFAULT,
+                              earlyGlSfOffsetNs != -1 ? earlyGlSfOffsetNs : sfVsyncPhaseOffsetNs,
+                              earlyGlAppOffsetNs != -1 ? earlyGlAppOffsetNs : vsyncPhaseOffsetNs};
+    defaultOffsets.late = {RefreshRateType::DEFAULT, sfVsyncPhaseOffsetNs, vsyncPhaseOffsetNs};
 
-    mHighRefreshRateOffsets.early = {highFpsEarlySfOffsetNs != -1 ? highFpsEarlySfOffsetNs
-                                                                  : highFpsLateSfOffsetNs,
-                                     highFpsEarlyAppOffsetNs != -1 ? highFpsEarlyAppOffsetNs
-                                                                   : highFpsLateAppOffsetNs};
-    mHighRefreshRateOffsets.earlyGl = {highFpsEarlyGlSfOffsetNs != -1 ? highFpsEarlyGlSfOffsetNs
-                                                                      : highFpsLateSfOffsetNs,
-                                       highFpsEarlyGlAppOffsetNs != -1 ? highFpsEarlyGlAppOffsetNs
-                                                                       : highFpsLateAppOffsetNs};
-    mHighRefreshRateOffsets.late = {highFpsLateSfOffsetNs, highFpsLateAppOffsetNs};
+    highFpsOffsets.early = {RefreshRateType::PERFORMANCE,
+                            highFpsEarlySfOffsetNs != -1 ? highFpsEarlySfOffsetNs
+                                                         : highFpsLateSfOffsetNs,
+                            highFpsEarlyAppOffsetNs != -1 ? highFpsEarlyAppOffsetNs
+                                                          : highFpsLateAppOffsetNs};
+    highFpsOffsets.earlyGl = {RefreshRateType::PERFORMANCE,
+                              highFpsEarlyGlSfOffsetNs != -1 ? highFpsEarlyGlSfOffsetNs
+                                                             : highFpsLateSfOffsetNs,
+                              highFpsEarlyGlAppOffsetNs != -1 ? highFpsEarlyGlAppOffsetNs
+                                                              : highFpsLateAppOffsetNs};
+    highFpsOffsets.late = {RefreshRateType::PERFORMANCE, highFpsLateSfOffsetNs,
+                           highFpsLateAppOffsetNs};
+
+    mOffsets.insert({RefreshRateType::POWER_SAVING, defaultOffsets});
+    mOffsets.insert({RefreshRateType::DEFAULT, defaultOffsets});
+    mOffsets.insert({RefreshRateType::PERFORMANCE, highFpsOffsets});
 
     mOffsetThresholdForNextVsync = phaseOffsetThresholdForNextVsyncNs != -1
             ? phaseOffsetThresholdForNextVsyncNs
@@ -99,12 +107,7 @@
 
 PhaseOffsets::Offsets PhaseOffsets::getOffsetsForRefreshRate(
         android::scheduler::RefreshRateConfigs::RefreshRateType refreshRateType) const {
-    switch (refreshRateType) {
-        case RefreshRateConfigs::RefreshRateType::PERFORMANCE:
-            return mHighRefreshRateOffsets;
-        default:
-            return mDefaultRefreshRateOffsets;
-    }
+    return mOffsets.at(refreshRateType);
 }
 
 void PhaseOffsets::dump(std::string& result) const {
diff --git a/services/surfaceflinger/Scheduler/PhaseOffsets.h b/services/surfaceflinger/Scheduler/PhaseOffsets.h
index dc71e6e..2b5c2f1 100644
--- a/services/surfaceflinger/Scheduler/PhaseOffsets.h
+++ b/services/surfaceflinger/Scheduler/PhaseOffsets.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <cinttypes>
+#include <unordered_map>
 
 #include "RefreshRateConfigs.h"
 #include "VSyncModulator.h"
@@ -79,14 +80,10 @@
     void dump(std::string& result) const override;
 
 private:
-    Offsets getDefaultRefreshRateOffsets() { return mDefaultRefreshRateOffsets; }
-    Offsets getHighRefreshRateOffsets() { return mHighRefreshRateOffsets; }
-
     std::atomic<RefreshRateConfigs::RefreshRateType> mRefreshRateType =
             RefreshRateConfigs::RefreshRateType::DEFAULT;
 
-    Offsets mDefaultRefreshRateOffsets;
-    Offsets mHighRefreshRateOffsets;
+    std::unordered_map<RefreshRateConfigs::RefreshRateType, Offsets> mOffsets;
     nsecs_t mOffsetThresholdForNextVsync;
 };
 } // namespace impl
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 513436a..a194106 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -76,6 +76,7 @@
     mSupportKernelTimer = support_kernel_idle_timer(false);
 
     mSetTouchTimerMs = set_touch_timer_ms(0);
+    mSetDisplayPowerTimerMs = set_display_power_timer_ms(0);
 
     char value[PROPERTY_VALUE_MAX];
     property_get("debug.sf.set_idle_timer_ms", value, "0");
@@ -110,26 +111,40 @@
                                                        [this] { expiredTouchTimerCallback(); });
         mTouchTimer->start();
     }
+
+    if (mSetDisplayPowerTimerMs > 0) {
+        mDisplayPowerTimer =
+                std::make_unique<scheduler::IdleTimer>(std::chrono::milliseconds(
+                                                               mSetDisplayPowerTimerMs),
+                                                       [this] { resetDisplayPowerTimerCallback(); },
+                                                       [this] {
+                                                           expiredDisplayPowerTimerCallback();
+                                                       });
+        mDisplayPowerTimer->start();
+    }
 }
 
 Scheduler::~Scheduler() {
     // Ensure the IdleTimer thread is joined before we start destroying state.
+    mDisplayPowerTimer.reset();
     mTouchTimer.reset();
     mIdleTimer.reset();
 }
 
 sp<Scheduler::ConnectionHandle> Scheduler::createConnection(
-        const char* connectionName, int64_t phaseOffsetNs, ResyncCallback resyncCallback,
+        const char* connectionName, nsecs_t phaseOffsetNs, nsecs_t offsetThresholdForNextVsync,
+        ResyncCallback resyncCallback,
         impl::EventThread::InterceptVSyncsCallback interceptCallback) {
     const int64_t id = sNextId++;
     ALOGV("Creating a connection handle with ID: %" PRId64 "\n", id);
 
     std::unique_ptr<EventThread> eventThread =
             makeEventThread(connectionName, mPrimaryDispSync.get(), phaseOffsetNs,
-                            std::move(interceptCallback));
+                            offsetThresholdForNextVsync, std::move(interceptCallback));
 
     auto eventThreadConnection =
-            createConnectionInternal(eventThread.get(), std::move(resyncCallback));
+            createConnectionInternal(eventThread.get(), std::move(resyncCallback),
+                                     ISurfaceComposer::eConfigChangedSuppress);
     mConnections.emplace(id,
                          std::make_unique<Connection>(new ConnectionHandle(id),
                                                       eventThreadConnection,
@@ -138,24 +153,28 @@
 }
 
 std::unique_ptr<EventThread> Scheduler::makeEventThread(
-        const char* connectionName, DispSync* dispSync, int64_t phaseOffsetNs,
+        const char* connectionName, DispSync* dispSync, nsecs_t phaseOffsetNs,
+        nsecs_t offsetThresholdForNextVsync,
         impl::EventThread::InterceptVSyncsCallback interceptCallback) {
     std::unique_ptr<VSyncSource> eventThreadSource =
-            std::make_unique<DispSyncSource>(dispSync, phaseOffsetNs, true, connectionName);
+            std::make_unique<DispSyncSource>(dispSync, phaseOffsetNs, offsetThresholdForNextVsync,
+                                             true, connectionName);
     return std::make_unique<impl::EventThread>(std::move(eventThreadSource),
                                                std::move(interceptCallback), connectionName);
 }
 
-sp<EventThreadConnection> Scheduler::createConnectionInternal(EventThread* eventThread,
-                                                              ResyncCallback&& resyncCallback) {
-    return eventThread->createEventConnection(std::move(resyncCallback));
+sp<EventThreadConnection> Scheduler::createConnectionInternal(
+        EventThread* eventThread, ResyncCallback&& resyncCallback,
+        ISurfaceComposer::ConfigChanged configChanged) {
+    return eventThread->createEventConnection(std::move(resyncCallback), configChanged);
 }
 
 sp<IDisplayEventConnection> Scheduler::createDisplayEventConnection(
-        const sp<Scheduler::ConnectionHandle>& handle, ResyncCallback resyncCallback) {
+        const sp<Scheduler::ConnectionHandle>& handle, ResyncCallback resyncCallback,
+        ISurfaceComposer::ConfigChanged configChanged) {
     RETURN_VALUE_IF_INVALID(nullptr);
     return createConnectionInternal(mConnections[handle->id]->thread.get(),
-                                    std::move(resyncCallback));
+                                    std::move(resyncCallback), configChanged);
 }
 
 EventThread* Scheduler::getEventThread(const sp<Scheduler::ConnectionHandle>& handle) {
@@ -280,13 +299,13 @@
     }
 }
 
-void Scheduler::addResyncSample(const nsecs_t timestamp, bool* periodChanged) {
+void Scheduler::addResyncSample(const nsecs_t timestamp, bool* periodFlushed) {
     bool needsHwVsync = false;
-    *periodChanged = false;
+    *periodFlushed = false;
     { // Scope for the lock
         std::lock_guard<std::mutex> lock(mHWVsyncLock);
         if (mPrimaryHWVsyncEnabled) {
-            needsHwVsync = mPrimaryDispSync->addResyncSample(timestamp, periodChanged);
+            needsHwVsync = mPrimaryDispSync->addResyncSample(timestamp, periodFlushed);
         }
     }
 
@@ -309,7 +328,7 @@
     mPrimaryDispSync->setIgnorePresentFences(ignore);
 }
 
-nsecs_t Scheduler::expectedPresentTime() {
+nsecs_t Scheduler::getDispSyncExpectedPresentTime() {
     return mPrimaryDispSync->expectedPresentTime();
 }
 
@@ -324,8 +343,11 @@
             : RefreshRateType::PERFORMANCE;
 
     const auto refreshRate = mRefreshRateConfigs.getRefreshRate(refreshRateType);
-    const uint32_t fps = (refreshRate) ? refreshRate->fps : 0;
-    return mLayerHistory.createLayer(name, fps);
+    const uint32_t performanceFps = (refreshRate) ? refreshRate->fps : 0;
+
+    const auto defaultRefreshRate = mRefreshRateConfigs.getRefreshRate(RefreshRateType::DEFAULT);
+    const uint32_t defaultFps = (defaultRefreshRate) ? defaultRefreshRate->fps : 0;
+    return mLayerHistory.createLayer(name, defaultFps, performanceFps);
 }
 
 void Scheduler::addLayerPresentTimeAndHDR(
@@ -371,11 +393,17 @@
 }
 
 void Scheduler::setChangeRefreshRateCallback(
-        const ChangeRefreshRateCallback& changeRefreshRateCallback) {
+        const ChangeRefreshRateCallback&& changeRefreshRateCallback) {
     std::lock_guard<std::mutex> lock(mCallbackLock);
     mChangeRefreshRateCallback = changeRefreshRateCallback;
 }
 
+void Scheduler::setGetCurrentRefreshRateTypeCallback(
+        const GetCurrentRefreshRateTypeCallback&& getCurrentRefreshRateTypeCallback) {
+    std::lock_guard<std::mutex> lock(mCallbackLock);
+    mGetCurrentRefreshRateTypeCallback = getCurrentRefreshRateTypeCallback;
+}
+
 void Scheduler::setGetVsyncPeriodCallback(const GetVsyncPeriod&& getVsyncPeriod) {
     std::lock_guard<std::mutex> lock(mCallbackLock);
     mGetVsyncPeriod = getVsyncPeriod;
@@ -404,43 +432,81 @@
     if (mSupportKernelTimer) {
         resetIdleTimer();
     }
+
+    // Touch event will boost the refresh rate to performance.
+    // Clear Layer History to get fresh FPS detection
+    mLayerHistory.clearHistory();
+}
+
+void Scheduler::setDisplayPowerState(bool normal) {
+    {
+        std::lock_guard<std::mutex> lock(mFeatureStateLock);
+        mIsDisplayPowerStateNormal = normal;
+    }
+
+    if (mDisplayPowerTimer) {
+        mDisplayPowerTimer->reset();
+    }
+
+    // Display Power event will boost the refresh rate to performance.
+    // Clear Layer History to get fresh FPS detection
+    mLayerHistory.clearHistory();
 }
 
 void Scheduler::resetTimerCallback() {
-    timerChangeRefreshRate(IdleTimerState::RESET);
+    handleTimerStateChanged(&mCurrentIdleTimerState, IdleTimerState::RESET, false);
     ATRACE_INT("ExpiredIdleTimer", 0);
 }
 
 void Scheduler::resetKernelTimerCallback() {
     ATRACE_INT("ExpiredKernelIdleTimer", 0);
     std::lock_guard<std::mutex> lock(mCallbackLock);
-    if (mGetVsyncPeriod) {
-        resyncToHardwareVsync(false, mGetVsyncPeriod());
+    if (mGetVsyncPeriod && mGetCurrentRefreshRateTypeCallback) {
+        // If we're not in performance mode then the kernel timer shouldn't do
+        // anything, as the refresh rate during DPU power collapse will be the
+        // same.
+        if (mGetCurrentRefreshRateTypeCallback() == Scheduler::RefreshRateType::PERFORMANCE) {
+            resyncToHardwareVsync(true, mGetVsyncPeriod());
+        }
     }
 }
 
 void Scheduler::expiredTimerCallback() {
-    timerChangeRefreshRate(IdleTimerState::EXPIRED);
+    handleTimerStateChanged(&mCurrentIdleTimerState, IdleTimerState::EXPIRED, false);
     ATRACE_INT("ExpiredIdleTimer", 1);
 }
 
 void Scheduler::resetTouchTimerCallback() {
-    // We do not notify the applications about config changes when idle timer is reset.
-    touchChangeRefreshRate(TouchState::ACTIVE);
+    handleTimerStateChanged(&mCurrentTouchState, TouchState::ACTIVE, true);
     ATRACE_INT("TouchState", 1);
 }
 
 void Scheduler::expiredTouchTimerCallback() {
-    // We do not notify the applications about config changes when idle timer expires.
-    touchChangeRefreshRate(TouchState::INACTIVE);
+    handleTimerStateChanged(&mCurrentTouchState, TouchState::INACTIVE, true);
     ATRACE_INT("TouchState", 0);
 }
 
+void Scheduler::resetDisplayPowerTimerCallback() {
+    handleTimerStateChanged(&mDisplayPowerTimerState, DisplayPowerTimerState::RESET, true);
+    ATRACE_INT("ExpiredDisplayPowerTimer", 0);
+}
+
+void Scheduler::expiredDisplayPowerTimerCallback() {
+    handleTimerStateChanged(&mDisplayPowerTimerState, DisplayPowerTimerState::EXPIRED, true);
+    ATRACE_INT("ExpiredDisplayPowerTimer", 1);
+}
+
 void Scheduler::expiredKernelTimerCallback() {
+    std::lock_guard<std::mutex> lock(mCallbackLock);
     ATRACE_INT("ExpiredKernelIdleTimer", 1);
-    // Disable HW Vsync if the timer expired, as we don't need it
-    // enabled if we're not pushing frames.
-    disableHardwareVsync(false);
+    if (mGetCurrentRefreshRateTypeCallback) {
+        if (mGetCurrentRefreshRateTypeCallback() != Scheduler::RefreshRateType::PERFORMANCE) {
+            // Disable HW Vsync if the timer expired, as we don't need it
+            // enabled if we're not pushing frames, and if we're in PERFORMANCE
+            // mode then we'll need to re-update the DispSync model anyways.
+            disableHardwareVsync(false);
+        }
+    }
 }
 
 std::string Scheduler::doDump() {
@@ -450,39 +516,23 @@
     return stream.str();
 }
 
-void Scheduler::timerChangeRefreshRate(IdleTimerState idleTimerState) {
-    RefreshRateType newRefreshRateType;
-    {
-        std::lock_guard<std::mutex> lock(mFeatureStateLock);
-        if (mCurrentIdleTimerState == idleTimerState) {
-            return;
-        }
-        mCurrentIdleTimerState = idleTimerState;
-        newRefreshRateType = calculateRefreshRateType();
-        if (mRefreshRateType == newRefreshRateType) {
-            return;
-        }
-        mRefreshRateType = newRefreshRateType;
-    }
-    changeRefreshRate(newRefreshRateType, ConfigEvent::None);
-}
-
-void Scheduler::touchChangeRefreshRate(TouchState touchState) {
+template <class T>
+void Scheduler::handleTimerStateChanged(T* currentState, T newState, bool eventOnContentDetection) {
     ConfigEvent event = ConfigEvent::None;
     RefreshRateType newRefreshRateType;
     {
         std::lock_guard<std::mutex> lock(mFeatureStateLock);
-        if (mCurrentTouchState == touchState) {
+        if (*currentState == newState) {
             return;
         }
-        mCurrentTouchState = touchState;
+        *currentState = newState;
         newRefreshRateType = calculateRefreshRateType();
         if (mRefreshRateType == newRefreshRateType) {
             return;
         }
         mRefreshRateType = newRefreshRateType;
-        // Send an event in case that content detection is on as touch has a higher priority
-        if (mCurrentContentFeatureState == ContentFeatureState::CONTENT_DETECTION_ON) {
+        if (eventOnContentDetection &&
+            mCurrentContentFeatureState == ContentFeatureState::CONTENT_DETECTION_ON) {
             event = ConfigEvent::Changed;
         }
     }
@@ -495,6 +545,12 @@
         return RefreshRateType::DEFAULT;
     }
 
+    // If Display Power is not in normal operation we want to be in performance mode.
+    // When coming back to normal mode, a grace period is given with DisplayPowerTimer
+    if (!mIsDisplayPowerStateNormal || mDisplayPowerTimerState == DisplayPowerTimerState::RESET) {
+        return RefreshRateType::PERFORMANCE;
+    }
+
     // As long as touch is active we want to be in performance mode
     if (mCurrentTouchState == TouchState::ACTIVE) {
         return RefreshRateType::PERFORMANCE;
@@ -510,22 +566,19 @@
         return RefreshRateType::PERFORMANCE;
     }
 
-    // Content detection is on, find the appropriate refresh rate
-    // Start with the smallest refresh rate which is within a margin of the content
-    RefreshRateType currRefreshRateType = RefreshRateType::PERFORMANCE;
-    constexpr float MARGIN = 0.05f;
-    auto iter = mRefreshRateConfigs.getRefreshRates().cbegin();
-    while (iter != mRefreshRateConfigs.getRefreshRates().cend()) {
-        if (iter->second->fps >= mContentRefreshRate * (1 - MARGIN)) {
-            currRefreshRateType = iter->first;
-            break;
-        }
-        ++iter;
-    }
+    // Content detection is on, find the appropriate refresh rate with minimal error
+    auto iter = min_element(mRefreshRateConfigs.getRefreshRates().cbegin(),
+                            mRefreshRateConfigs.getRefreshRates().cend(),
+                            [rate = mContentRefreshRate](const auto& l, const auto& r) -> bool {
+                                return std::abs(l.second->fps - static_cast<float>(rate)) <
+                                        std::abs(r.second->fps - static_cast<float>(rate));
+                            });
+    RefreshRateType currRefreshRateType = iter->first;
 
     // Some content aligns better on higher refresh rate. For example for 45fps we should choose
     // 90Hz config. However we should still prefer a lower refresh rate if the content doesn't
     // align well with both
+    constexpr float MARGIN = 0.05f;
     float ratio = mRefreshRateConfigs.getRefreshRate(currRefreshRateType)->fps /
             float(mContentRefreshRate);
     if (std::abs(std::round(ratio) - ratio) > MARGIN) {
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 96d4bd5..5d8bb4c 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -49,6 +49,7 @@
     }
 
     using RefreshRateType = scheduler::RefreshRateConfigs::RefreshRateType;
+    using GetCurrentRefreshRateTypeCallback = std::function<RefreshRateType()>;
     using ChangeRefreshRateCallback = std::function<void(RefreshRateType, ConfigEvent)>;
     using GetVsyncPeriod = std::function<nsecs_t()>;
 
@@ -96,12 +97,13 @@
     virtual ~Scheduler();
 
     /** Creates an EventThread connection. */
-    sp<ConnectionHandle> createConnection(const char* connectionName, int64_t phaseOffsetNs,
-                                          ResyncCallback,
+    sp<ConnectionHandle> createConnection(const char* connectionName, nsecs_t phaseOffsetNs,
+                                          nsecs_t offsetThresholdForNextVsync, ResyncCallback,
                                           impl::EventThread::InterceptVSyncsCallback);
 
-    sp<IDisplayEventConnection> createDisplayEventConnection(const sp<ConnectionHandle>& handle,
-                                                             ResyncCallback);
+    sp<IDisplayEventConnection> createDisplayEventConnection(
+            const sp<ConnectionHandle>& handle, ResyncCallback,
+            ISurfaceComposer::ConfigChanged configChanged);
 
     // Getter methods.
     EventThread* getEventThread(const sp<ConnectionHandle>& handle);
@@ -135,16 +137,21 @@
 
     void enableHardwareVsync();
     void disableHardwareVsync(bool makeUnavailable);
+    // Resyncs the scheduler to hardware vsync.
+    // If makeAvailable is true, then hardware vsync will be turned on.
+    // Otherwise, if hardware vsync is not already enabled then this method will
+    // no-op.
+    // The period is the vsync period from the current display configuration.
     void resyncToHardwareVsync(bool makeAvailable, nsecs_t period);
     // Creates a callback for resyncing.
     ResyncCallback makeResyncCallback(GetVsyncPeriod&& getVsyncPeriod);
     void setRefreshSkipCount(int count);
-    // Passes a vsync sample to DispSync. periodChange will be true if DipSync
-    // detected that the vsync period changed, and false otherwise.
-    void addResyncSample(const nsecs_t timestamp, bool* periodChanged);
+    // Passes a vsync sample to DispSync. periodFlushed will be true if
+    // DispSync detected that the vsync period changed, and false otherwise.
+    void addResyncSample(const nsecs_t timestamp, bool* periodFlushed);
     void addPresentFence(const std::shared_ptr<FenceTime>& fenceTime);
     void setIgnorePresentFences(bool ignore);
-    nsecs_t expectedPresentTime();
+    nsecs_t getDispSyncExpectedPresentTime();
     // Registers the layer in the scheduler, and returns the handle for future references.
     std::unique_ptr<scheduler::LayerHistory::LayerHandle> registerLayer(std::string const& name,
                                                                         int windowType);
@@ -159,7 +166,9 @@
     // Updates FPS based on the most content presented.
     void updateFpsBasedOnContent();
     // Callback that gets invoked when Scheduler wants to change the refresh rate.
-    void setChangeRefreshRateCallback(const ChangeRefreshRateCallback& changeRefreshRateCallback);
+    void setChangeRefreshRateCallback(const ChangeRefreshRateCallback&& changeRefreshRateCallback);
+    void setGetCurrentRefreshRateTypeCallback(
+            const GetCurrentRefreshRateTypeCallback&& getCurrentRefreshRateType);
     void setGetVsyncPeriodCallback(const GetVsyncPeriod&& getVsyncPeriod);
 
     // Returns whether idle timer is enabled or not
@@ -171,6 +180,9 @@
     // Function that resets the touch timer.
     void notifyTouchEvent();
 
+    // Function that sets whether display power mode is normal or not.
+    void setDisplayPowerState(bool normal);
+
     // Returns relevant information about Scheduler for dumpsys purposes.
     std::string doDump();
 
@@ -179,7 +191,8 @@
 
 protected:
     virtual std::unique_ptr<EventThread> makeEventThread(
-            const char* connectionName, DispSync* dispSync, int64_t phaseOffsetNs,
+            const char* connectionName, DispSync* dispSync, nsecs_t phaseOffsetNs,
+            nsecs_t offsetThresholdForNextVsync,
             impl::EventThread::InterceptVSyncsCallback interceptCallback);
 
 private:
@@ -190,9 +203,11 @@
     enum class ContentFeatureState { CONTENT_DETECTION_ON, CONTENT_DETECTION_OFF };
     enum class IdleTimerState { EXPIRED, RESET };
     enum class TouchState { INACTIVE, ACTIVE };
+    enum class DisplayPowerTimerState { EXPIRED, RESET };
 
     // Creates a connection on the given EventThread and forwards the given callbacks.
-    sp<EventThreadConnection> createConnectionInternal(EventThread*, ResyncCallback&&);
+    sp<EventThreadConnection> createConnectionInternal(EventThread*, ResyncCallback&&,
+                                                       ISurfaceComposer::ConfigChanged);
 
     nsecs_t calculateAverage() const;
     void updateFrameSkipping(const int64_t skipCount);
@@ -213,12 +228,15 @@
     void resetTouchTimerCallback();
     // Function that is called when the touch timer expires.
     void expiredTouchTimerCallback();
+    // Function that is called when the display power timer resets.
+    void resetDisplayPowerTimerCallback();
+    // Function that is called when the display power timer expires.
+    void expiredDisplayPowerTimerCallback();
     // Sets vsync period.
     void setVsyncPeriod(const nsecs_t period);
-    // Idle timer feature's function to change the refresh rate.
-    void timerChangeRefreshRate(IdleTimerState idleTimerState);
-    // Touch timer feature's function to change the refresh rate.
-    void touchChangeRefreshRate(TouchState touchState);
+    // handles various timer features to change the refresh rate.
+    template <class T>
+    void handleTimerStateChanged(T* currentState, T newState, bool eventOnContentDetection);
     // Calculate the new refresh rate type
     RefreshRateType calculateRefreshRateType() REQUIRES(mFeatureStateLock);
     // Acquires a lock and calls the ChangeRefreshRateCallback() with given parameters.
@@ -274,7 +292,12 @@
     int64_t mSetTouchTimerMs = 0;
     std::unique_ptr<scheduler::IdleTimer> mTouchTimer;
 
+    // Timer used to monitor display power mode.
+    int64_t mSetDisplayPowerTimerMs = 0;
+    std::unique_ptr<scheduler::IdleTimer> mDisplayPowerTimer;
+
     std::mutex mCallbackLock;
+    GetCurrentRefreshRateTypeCallback mGetCurrentRefreshRateTypeCallback GUARDED_BY(mCallbackLock);
     ChangeRefreshRateCallback mChangeRefreshRateCallback GUARDED_BY(mCallbackLock);
     GetVsyncPeriod mGetVsyncPeriod GUARDED_BY(mCallbackLock);
 
@@ -285,14 +308,17 @@
             ContentFeatureState::CONTENT_DETECTION_OFF;
     IdleTimerState mCurrentIdleTimerState GUARDED_BY(mFeatureStateLock) = IdleTimerState::RESET;
     TouchState mCurrentTouchState GUARDED_BY(mFeatureStateLock) = TouchState::INACTIVE;
+    DisplayPowerTimerState mDisplayPowerTimerState GUARDED_BY(mFeatureStateLock) =
+            DisplayPowerTimerState::EXPIRED;
     uint32_t mContentRefreshRate GUARDED_BY(mFeatureStateLock);
     RefreshRateType mRefreshRateType GUARDED_BY(mFeatureStateLock);
     bool mIsHDRContent GUARDED_BY(mFeatureStateLock) = false;
+    bool mIsDisplayPowerStateNormal GUARDED_BY(mFeatureStateLock) = true;
 
     const scheduler::RefreshRateConfigs& mRefreshRateConfigs;
 
     // Global config to force HDR content to work on DEFAULT refreshRate
-    static constexpr bool mForceHDRContentToDefaultRefreshRate = true;
+    static constexpr bool mForceHDRContentToDefaultRefreshRate = false;
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/Scheduler/SchedulerUtils.h b/services/surfaceflinger/Scheduler/SchedulerUtils.h
index 3bf3922..ced1899 100644
--- a/services/surfaceflinger/Scheduler/SchedulerUtils.h
+++ b/services/surfaceflinger/Scheduler/SchedulerUtils.h
@@ -36,13 +36,16 @@
 static constexpr int SCREEN_OFF_CONFIG_ID = -1;
 static constexpr uint32_t HWC2_SCREEN_OFF_CONFIG_ID = 0xffffffff;
 
-// This number is used when we try to determine how long does a given layer stay relevant.
-// Currently it is set to 100ms, because that would indicate 10Hz rendering.
-static constexpr std::chrono::nanoseconds TIME_EPSILON_NS = 100ms;
-
 // This number is used when we try to determine how long do we keep layer information around
-// before we remove it. Currently it is set to 100ms.
-static constexpr std::chrono::nanoseconds OBSOLETE_TIME_EPSILON_NS = 100ms;
+// before we remove it. It is also used to determine how long the layer stays relevant.
+// This time period captures infrequent updates when playing YouTube video with static image,
+// or waiting idle in messaging app, when cursor is blinking.
+static constexpr std::chrono::nanoseconds OBSOLETE_TIME_EPSILON_NS = 1200ms;
+
+// Layer is considered low activity if the buffers come more than LOW_ACTIVITY_EPSILON_NS
+// apart. This is helping SF to vote for lower refresh rates when there is not activity
+// in screen.
+static constexpr std::chrono::nanoseconds LOW_ACTIVITY_EPSILON_NS = 250ms;
 
 // Calculates the statistical mean (average) in the data structure (array, vector). The
 // function does not modify the contents of the array.
diff --git a/services/surfaceflinger/Scheduler/VSyncModulator.cpp b/services/surfaceflinger/Scheduler/VSyncModulator.cpp
new file mode 100644
index 0000000..7a3bf8e
--- /dev/null
+++ b/services/surfaceflinger/Scheduler/VSyncModulator.cpp
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
+#include "VSyncModulator.h"
+
+#include <cutils/properties.h>
+#include <utils/Trace.h>
+
+#include <cinttypes>
+#include <mutex>
+
+namespace android {
+
+using RefreshRateType = scheduler::RefreshRateConfigs::RefreshRateType;
+VSyncModulator::VSyncModulator() {
+    char value[PROPERTY_VALUE_MAX];
+    property_get("debug.sf.vsync_trace_detailed_info", value, "0");
+    mTraceDetailedInfo = atoi(value);
+    // Populate the offset map with some default offsets.
+    const Offsets defaultOffsets = {RefreshRateType::DEFAULT, 0, 0};
+    setPhaseOffsets(defaultOffsets, defaultOffsets, defaultOffsets, 0);
+}
+
+void VSyncModulator::setPhaseOffsets(Offsets early, Offsets earlyGl, Offsets late,
+                                     nsecs_t thresholdForNextVsync) {
+    std::lock_guard<std::mutex> lock(mMutex);
+    mOffsetMap.insert_or_assign(OffsetType::Early, early);
+    mOffsetMap.insert_or_assign(OffsetType::EarlyGl, earlyGl);
+    mOffsetMap.insert_or_assign(OffsetType::Late, late);
+    mThresholdForNextVsync = thresholdForNextVsync;
+    updateOffsetsLocked();
+}
+
+void VSyncModulator::setTransactionStart(Scheduler::TransactionStart transactionStart) {
+    if (transactionStart == Scheduler::TransactionStart::EARLY) {
+        mRemainingEarlyFrameCount = MIN_EARLY_FRAME_COUNT_TRANSACTION;
+    }
+
+    // An early transaction stays an early transaction.
+    if (transactionStart == mTransactionStart ||
+        mTransactionStart == Scheduler::TransactionStart::EARLY) {
+        return;
+    }
+    mTransactionStart = transactionStart;
+    updateOffsets();
+}
+
+void VSyncModulator::onTransactionHandled() {
+    if (mTransactionStart == Scheduler::TransactionStart::NORMAL) return;
+    mTransactionStart = Scheduler::TransactionStart::NORMAL;
+    updateOffsets();
+}
+
+void VSyncModulator::onRefreshRateChangeInitiated() {
+    if (mRefreshRateChangePending) {
+        return;
+    }
+    mRefreshRateChangePending = true;
+    updateOffsets();
+}
+
+void VSyncModulator::onRefreshRateChangeCompleted() {
+    if (!mRefreshRateChangePending) {
+        return;
+    }
+    mRefreshRateChangePending = false;
+    updateOffsets();
+}
+
+void VSyncModulator::onRefreshed(bool usedRenderEngine) {
+    bool updateOffsetsNeeded = false;
+    if (mRemainingEarlyFrameCount > 0) {
+        mRemainingEarlyFrameCount--;
+        updateOffsetsNeeded = true;
+    }
+    if (usedRenderEngine) {
+        mRemainingRenderEngineUsageCount = MIN_EARLY_GL_FRAME_COUNT_TRANSACTION;
+        updateOffsetsNeeded = true;
+    } else if (mRemainingRenderEngineUsageCount > 0) {
+        mRemainingRenderEngineUsageCount--;
+        updateOffsetsNeeded = true;
+    }
+    if (updateOffsetsNeeded) {
+        updateOffsets();
+    }
+}
+
+VSyncModulator::Offsets VSyncModulator::getOffsets() {
+    std::lock_guard<std::mutex> lock(mMutex);
+    return mOffsets;
+}
+
+VSyncModulator::Offsets VSyncModulator::getNextOffsets() {
+    return mOffsetMap.at(getNextOffsetType());
+}
+
+VSyncModulator::OffsetType VSyncModulator::getNextOffsetType() {
+    // Early offsets are used if we're in the middle of a refresh rate
+    // change, or if we recently begin a transaction.
+    if (mTransactionStart == Scheduler::TransactionStart::EARLY || mRemainingEarlyFrameCount > 0 ||
+        mRefreshRateChangePending) {
+        return OffsetType::Early;
+    } else if (mRemainingRenderEngineUsageCount > 0) {
+        return OffsetType::EarlyGl;
+    } else {
+        return OffsetType::Late;
+    }
+}
+
+void VSyncModulator::updateOffsets() {
+    std::lock_guard<std::mutex> lock(mMutex);
+    updateOffsetsLocked();
+}
+
+void VSyncModulator::updateOffsetsLocked() {
+    const Offsets desired = getNextOffsets();
+
+    if (mSfConnectionHandle != nullptr) {
+        mScheduler->setPhaseOffset(mSfConnectionHandle, desired.sf);
+    }
+
+    if (mAppConnectionHandle != nullptr) {
+        mScheduler->setPhaseOffset(mAppConnectionHandle, desired.app);
+    }
+
+    flushOffsets();
+}
+
+void VSyncModulator::flushOffsets() {
+    OffsetType type = getNextOffsetType();
+    mOffsets = mOffsetMap.at(type);
+    if (!mTraceDetailedInfo) {
+        return;
+    }
+    ATRACE_INT("Vsync-EarlyOffsetsOn",
+               mOffsets.fpsMode == RefreshRateType::DEFAULT && type == OffsetType::Early);
+    ATRACE_INT("Vsync-EarlyGLOffsetsOn",
+               mOffsets.fpsMode == RefreshRateType::DEFAULT && type == OffsetType::EarlyGl);
+    ATRACE_INT("Vsync-LateOffsetsOn",
+               mOffsets.fpsMode == RefreshRateType::DEFAULT && type == OffsetType::Late);
+    ATRACE_INT("Vsync-HighFpsEarlyOffsetsOn",
+               mOffsets.fpsMode == RefreshRateType::PERFORMANCE && type == OffsetType::Early);
+    ATRACE_INT("Vsync-HighFpsEarlyGLOffsetsOn",
+               mOffsets.fpsMode == RefreshRateType::PERFORMANCE && type == OffsetType::EarlyGl);
+    ATRACE_INT("Vsync-HighFpsLateOffsetsOn",
+               mOffsets.fpsMode == RefreshRateType::PERFORMANCE && type == OffsetType::Late);
+}
+
+} // namespace android
diff --git a/services/surfaceflinger/Scheduler/VSyncModulator.h b/services/surfaceflinger/Scheduler/VSyncModulator.h
index 81a7864..ddbd221 100644
--- a/services/surfaceflinger/Scheduler/VSyncModulator.h
+++ b/services/surfaceflinger/Scheduler/VSyncModulator.h
@@ -16,8 +16,6 @@
 
 #pragma once
 
-#include <utils/Errors.h>
-
 #include <cinttypes>
 #include <mutex>
 
@@ -35,12 +33,28 @@
     // sending new transactions.
     const int MIN_EARLY_FRAME_COUNT_TRANSACTION = 2;
 
+    // Number of frames we'll keep the early gl phase offsets once they are activated.
+    // This acts as a low-pass filter to avoid scenarios where we rapidly
+    // switch in and out of gl composition.
+    const int MIN_EARLY_GL_FRAME_COUNT_TRANSACTION = 2;
+
 public:
+    VSyncModulator();
+
+    // Wrapper for a collection of surfaceflinger/app offsets for a particular
+    // configuration .
     struct Offsets {
+        scheduler::RefreshRateConfigs::RefreshRateType fpsMode;
         nsecs_t sf;
         nsecs_t app;
     };
 
+    enum class OffsetType {
+        Early,
+        EarlyGl,
+        Late,
+    };
+
     // Sets the phase offsets
     //
     // sfEarly: The phase offset when waking up SF early, which happens when marking a transaction
@@ -51,31 +65,10 @@
     // appEarly: Like sfEarly, but for the app-vsync
     // appEarlyGl: Like sfEarlyGl, but for the app-vsync.
     // appLate: The regular app vsync phase offset.
-    void setPhaseOffsets(Offsets early, Offsets earlyGl, Offsets late) {
-        mEarlyOffsets = early;
-        mEarlyGlOffsets = earlyGl;
-        mLateOffsets = late;
+    void setPhaseOffsets(Offsets early, Offsets earlyGl, Offsets late,
+                         nsecs_t thresholdForNextVsync) EXCLUDES(mMutex);
 
-        if (mSfConnectionHandle && late.sf != mOffsets.load().sf) {
-            mScheduler->setPhaseOffset(mSfConnectionHandle, late.sf);
-        }
-
-        if (mAppConnectionHandle && late.app != mOffsets.load().app) {
-            mScheduler->setPhaseOffset(mAppConnectionHandle, late.app);
-        }
-
-        mOffsets = late;
-    }
-
-    Offsets getEarlyOffsets() const { return mEarlyOffsets; }
-
-    Offsets getEarlyGlOffsets() const { return mEarlyGlOffsets; }
-
-    void setEventThreads(EventThread* sfEventThread, EventThread* appEventThread) {
-        mSfEventThread = sfEventThread;
-        mAppEventThread = appEventThread;
-    }
-
+    // Sets the scheduler and vsync connection handlers.
     void setSchedulerAndHandles(Scheduler* scheduler,
                                 Scheduler::ConnectionHandle* appConnectionHandle,
                                 Scheduler::ConnectionHandle* sfConnectionHandle) {
@@ -84,120 +77,57 @@
         mSfConnectionHandle = sfConnectionHandle;
     }
 
-    void setTransactionStart(Scheduler::TransactionStart transactionStart) {
-        if (transactionStart == Scheduler::TransactionStart::EARLY) {
-            mRemainingEarlyFrameCount = MIN_EARLY_FRAME_COUNT_TRANSACTION;
-        }
+    // Signals that a transaction has started, and changes offsets accordingly.
+    void setTransactionStart(Scheduler::TransactionStart transactionStart);
 
-        // An early transaction stays an early transaction.
-        if (transactionStart == mTransactionStart ||
-            mTransactionStart == Scheduler::TransactionStart::EARLY) {
-            return;
-        }
-        mTransactionStart = transactionStart;
-        updateOffsets();
-    }
-
-    void onTransactionHandled() {
-        if (mTransactionStart == Scheduler::TransactionStart::NORMAL) return;
-        mTransactionStart = Scheduler::TransactionStart::NORMAL;
-        updateOffsets();
-    }
+    // Signals that a transaction has been completed, so that we can finish
+    // special handling for a transaction.
+    void onTransactionHandled();
 
     // Called when we send a refresh rate change to hardware composer, so that
     // we can move into early offsets.
-    void onRefreshRateChangeInitiated() {
-        if (mRefreshRateChangePending) {
-            return;
-        }
-        mRefreshRateChangePending = true;
-        updateOffsets();
-    }
+    void onRefreshRateChangeInitiated();
 
     // Called when we detect from vsync signals that the refresh rate changed.
     // This way we can move out of early offsets if no longer necessary.
-    void onRefreshRateChangeDetected() {
-        if (!mRefreshRateChangePending) {
-            return;
-        }
-        mRefreshRateChangePending = false;
-        updateOffsets();
-    }
+    void onRefreshRateChangeCompleted();
 
-    void onRefreshed(bool usedRenderEngine) {
-        bool updateOffsetsNeeded = false;
-        if (mRemainingEarlyFrameCount > 0) {
-            mRemainingEarlyFrameCount--;
-            updateOffsetsNeeded = true;
-        }
-        if (usedRenderEngine != mLastFrameUsedRenderEngine) {
-            mLastFrameUsedRenderEngine = usedRenderEngine;
-            updateOffsetsNeeded = true;
-        }
-        if (updateOffsetsNeeded) {
-            updateOffsets();
-        }
-    }
+    // Called when the display is presenting a new frame. usedRenderEngine
+    // should be set to true if RenderEngine was involved with composing the new
+    // frame.
+    void onRefreshed(bool usedRenderEngine);
 
-    Offsets getOffsets() {
-        // Early offsets are used if we're in the middle of a refresh rate
-        // change, or if we recently begin a transaction.
-        if (mTransactionStart == Scheduler::TransactionStart::EARLY ||
-            mRemainingEarlyFrameCount > 0 || mRefreshRateChangePending) {
-            return mEarlyOffsets;
-        } else if (mLastFrameUsedRenderEngine) {
-            return mEarlyGlOffsets;
-        } else {
-            return mLateOffsets;
-        }
-    }
+    // Returns the offsets that we are currently using
+    Offsets getOffsets() EXCLUDES(mMutex);
 
 private:
-    void updateOffsets() {
-        const Offsets desired = getOffsets();
-        const Offsets current = mOffsets;
+    // Returns the next offsets that we should be using
+    Offsets getNextOffsets() REQUIRES(mMutex);
+    // Returns the next offset type that we should use.
+    OffsetType getNextOffsetType();
+    // Updates offsets and persists them into the scheduler framework.
+    void updateOffsets() EXCLUDES(mMutex);
+    void updateOffsetsLocked() REQUIRES(mMutex);
+    // Updates the internal offsets and offset type.
+    void flushOffsets() REQUIRES(mMutex);
 
-        bool changed = false;
-        if (desired.sf != current.sf) {
-            if (mSfConnectionHandle != nullptr) {
-                mScheduler->setPhaseOffset(mSfConnectionHandle, desired.sf);
-            } else {
-                mSfEventThread->setPhaseOffset(desired.sf);
-            }
-            changed = true;
-        }
-        if (desired.app != current.app) {
-            if (mAppConnectionHandle != nullptr) {
-                mScheduler->setPhaseOffset(mAppConnectionHandle, desired.app);
-            } else {
-                mAppEventThread->setPhaseOffset(desired.app);
-            }
-            changed = true;
-        }
-
-        if (changed) {
-            mOffsets = desired;
-        }
-    }
-
-    Offsets mLateOffsets;
-    Offsets mEarlyOffsets;
-    Offsets mEarlyGlOffsets;
-
-    EventThread* mSfEventThread = nullptr;
-    EventThread* mAppEventThread = nullptr;
+    mutable std::mutex mMutex;
+    std::unordered_map<OffsetType, Offsets> mOffsetMap GUARDED_BY(mMutex);
+    nsecs_t mThresholdForNextVsync;
 
     Scheduler* mScheduler = nullptr;
     Scheduler::ConnectionHandle* mAppConnectionHandle = nullptr;
     Scheduler::ConnectionHandle* mSfConnectionHandle = nullptr;
 
-    std::atomic<Offsets> mOffsets;
+    Offsets mOffsets GUARDED_BY(mMutex) = {Scheduler::RefreshRateType::DEFAULT, 0, 0};
 
     std::atomic<Scheduler::TransactionStart> mTransactionStart =
             Scheduler::TransactionStart::NORMAL;
-    std::atomic<bool> mLastFrameUsedRenderEngine = false;
     std::atomic<bool> mRefreshRateChangePending = false;
     std::atomic<int> mRemainingEarlyFrameCount = 0;
+    std::atomic<int> mRemainingRenderEngineUsageCount = 0;
+
+    bool mTraceDetailedInfo = false;
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index ad0ac6b..3a96f73 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -48,6 +48,8 @@
 #include <compositionengine/impl/OutputLayerCompositionState.h>
 #include <dvr/vr_flinger.h>
 #include <gui/BufferQueue.h>
+#include <gui/DebugEGLImageTracker.h>
+
 #include <gui/GuiConfig.h>
 #include <gui/IDisplayEventConnection.h>
 #include <gui/IProducerListener.h>
@@ -311,6 +313,9 @@
     wideColorGamutCompositionPixelFormat =
             static_cast<ui::PixelFormat>(wcg_composition_pixel_format(ui::PixelFormat::RGBA_8888));
 
+    mColorSpaceAgnosticDataspace =
+            static_cast<ui::Dataspace>(color_space_agnostic_dataspace(Dataspace::UNKNOWN));
+
     useContextPriority = use_context_priority(true);
 
     auto tmpPrimaryDisplayOrientation = primary_display_orientation(
@@ -382,7 +387,8 @@
     mLumaSampling = atoi(value);
 
     const auto [early, gl, late] = mPhaseOffsets->getCurrentOffsets();
-    mVsyncModulator.setPhaseOffsets(early, gl, late);
+    mVsyncModulator.setPhaseOffsets(early, gl, late,
+                                    mPhaseOffsets->getOffsetThresholdForNextVsync());
 
     // We should be reading 'persist.sys.sf.color_saturation' here
     // but since /data may be encrypted, we need to wait until after vold
@@ -621,13 +627,16 @@
             mScheduler->makeResyncCallback(std::bind(&SurfaceFlinger::getVsyncPeriod, this));
 
     mAppConnectionHandle =
-            mScheduler->createConnection("app", mPhaseOffsets->getCurrentAppOffset(),
+            mScheduler->createConnection("app", mVsyncModulator.getOffsets().app,
+                                         mPhaseOffsets->getOffsetThresholdForNextVsync(),
                                          resyncCallback,
                                          impl::EventThread::InterceptVSyncsCallback());
-    mSfConnectionHandle = mScheduler->createConnection("sf", mPhaseOffsets->getCurrentSfOffset(),
-                                                       resyncCallback, [this](nsecs_t timestamp) {
-                                                           mInterceptor->saveVSyncEvent(timestamp);
-                                                       });
+    mSfConnectionHandle =
+            mScheduler->createConnection("sf", mVsyncModulator.getOffsets().sf,
+                                         mPhaseOffsets->getOffsetThresholdForNextVsync(),
+                                         resyncCallback, [this](nsecs_t timestamp) {
+                                             mInterceptor->saveVSyncEvent(timestamp);
+                                         });
 
     mEventQueue->setEventConnection(mScheduler->getEventConnection(mSfConnectionHandle));
     mVsyncModulator.setSchedulerAndHandles(mScheduler.get(), mAppConnectionHandle.get(),
@@ -711,6 +720,24 @@
                 Mutex::Autolock lock(mStateLock);
                 setRefreshRateTo(type, event);
             });
+    mScheduler->setGetCurrentRefreshRateTypeCallback([this] {
+        Mutex::Autolock lock(mStateLock);
+        const auto display = getDefaultDisplayDeviceLocked();
+        if (!display) {
+            // If we don't have a default display the fallback to the default
+            // refresh rate type
+            return RefreshRateType::DEFAULT;
+        }
+
+        const int configId = display->getActiveConfig();
+        for (const auto& [type, refresh] : mRefreshRateConfigs.getRefreshRates()) {
+            if (refresh && refresh->configId == configId) {
+                return type;
+            }
+        }
+        // This should never happen, but just gracefully fallback to default.
+        return RefreshRateType::DEFAULT;
+    });
     mScheduler->setGetVsyncPeriodCallback([this] {
         Mutex::Autolock lock(mStateLock);
         return getVsyncPeriod();
@@ -940,10 +967,13 @@
         // Start receiving vsync samples now, so that we can detect a period
         // switch.
         mScheduler->resyncToHardwareVsync(true, getVsyncPeriod());
+        // As we called to set period, we will call to onRefreshRateChangeCompleted once
+        // DispSync model is locked.
+        mVsyncModulator.onRefreshRateChangeInitiated();
         mPhaseOffsets->setRefreshRateType(info.type);
         const auto [early, gl, late] = mPhaseOffsets->getCurrentOffsets();
-        mVsyncModulator.onRefreshRateChangeInitiated();
-        mVsyncModulator.setPhaseOffsets(early, gl, late);
+        mVsyncModulator.setPhaseOffsets(early, gl, late,
+                                        mPhaseOffsets->getOffsetThresholdForNextVsync());
     }
     mDesiredActiveConfigChanged = true;
     ATRACE_INT("DesiredActiveConfigChanged", mDesiredActiveConfigChanged);
@@ -975,10 +1005,10 @@
 
     display->setActiveConfig(mUpcomingActiveConfig.configId);
 
-    mScheduler->resyncToHardwareVsync(true, getVsyncPeriod());
     mPhaseOffsets->setRefreshRateType(mUpcomingActiveConfig.type);
     const auto [early, gl, late] = mPhaseOffsets->getCurrentOffsets();
-    mVsyncModulator.setPhaseOffsets(early, gl, late);
+    mVsyncModulator.setPhaseOffsets(early, gl, late,
+                                    mPhaseOffsets->getOffsetThresholdForNextVsync());
     ATRACE_INT("ActiveConfigMode", mUpcomingActiveConfig.configId);
 
     if (mUpcomingActiveConfig.event != Scheduler::ConfigEvent::None) {
@@ -987,6 +1017,19 @@
     }
 }
 
+void SurfaceFlinger::desiredActiveConfigChangeDone() {
+    std::lock_guard<std::mutex> lock(mActiveConfigLock);
+    mDesiredActiveConfig.event = Scheduler::ConfigEvent::None;
+    mDesiredActiveConfigChanged = false;
+    ATRACE_INT("DesiredActiveConfigChanged", mDesiredActiveConfigChanged);
+
+    mScheduler->resyncToHardwareVsync(true, getVsyncPeriod());
+    mPhaseOffsets->setRefreshRateType(mUpcomingActiveConfig.type);
+    const auto [early, gl, late] = mPhaseOffsets->getCurrentOffsets();
+    mVsyncModulator.setPhaseOffsets(early, gl, late,
+                                    mPhaseOffsets->getOffsetThresholdForNextVsync());
+}
+
 bool SurfaceFlinger::performSetActiveConfig() {
     ATRACE_CALL();
     if (mCheckPendingFence) {
@@ -1016,10 +1059,7 @@
     if (!display || display->getActiveConfig() == desiredActiveConfig.configId) {
         // display is not valid or we are already in the requested mode
         // on both cases there is nothing left to do
-        std::lock_guard<std::mutex> lock(mActiveConfigLock);
-        mDesiredActiveConfig.event = Scheduler::ConfigEvent::None;
-        mDesiredActiveConfigChanged = false;
-        ATRACE_INT("DesiredActiveConfigChanged", mDesiredActiveConfigChanged);
+        desiredActiveConfigChangeDone();
         return false;
     }
 
@@ -1027,13 +1067,10 @@
     // allowed configs might have change by the time we process the refresh.
     // Make sure the desired config is still allowed
     if (!isDisplayConfigAllowed(desiredActiveConfig.configId)) {
-        std::lock_guard<std::mutex> lock(mActiveConfigLock);
-        mDesiredActiveConfig.event = Scheduler::ConfigEvent::None;
-        mDesiredActiveConfig.configId = display->getActiveConfig();
-        mDesiredActiveConfigChanged = false;
-        ATRACE_INT("DesiredActiveConfigChanged", mDesiredActiveConfigChanged);
+        desiredActiveConfigChangeDone();
         return false;
     }
+
     mUpcomingActiveConfig = desiredActiveConfig;
     const auto displayId = display->getId();
     LOG_ALWAYS_FATAL_IF(!displayId);
@@ -1371,7 +1408,7 @@
 // ----------------------------------------------------------------------------
 
 sp<IDisplayEventConnection> SurfaceFlinger::createDisplayEventConnection(
-        ISurfaceComposer::VsyncSource vsyncSource) {
+        ISurfaceComposer::VsyncSource vsyncSource, ISurfaceComposer::ConfigChanged configChanged) {
     auto resyncCallback = mScheduler->makeResyncCallback([this] {
         Mutex::Autolock lock(mStateLock);
         return getVsyncPeriod();
@@ -1380,7 +1417,8 @@
     const auto& handle =
             vsyncSource == eVsyncSourceSurfaceFlinger ? mSfConnectionHandle : mAppConnectionHandle;
 
-    return mScheduler->createDisplayEventConnection(handle, std::move(resyncCallback));
+    return mScheduler->createDisplayEventConnection(handle, std::move(resyncCallback),
+                                                    configChanged);
 }
 
 // ----------------------------------------------------------------------------
@@ -1453,10 +1491,10 @@
         return;
     }
 
-    bool periodChanged = false;
-    mScheduler->addResyncSample(timestamp, &periodChanged);
-    if (periodChanged) {
-        mVsyncModulator.onRefreshRateChangeDetected();
+    bool periodFlushed = false;
+    mScheduler->addResyncSample(timestamp, &periodFlushed);
+    if (periodFlushed) {
+        mVsyncModulator.onRefreshRateChangeCompleted();
     }
 }
 
@@ -1529,10 +1567,23 @@
 
 void SurfaceFlinger::setPrimaryVsyncEnabled(bool enabled) {
     ATRACE_CALL();
-    Mutex::Autolock lock(mStateLock);
+
+    // Enable / Disable HWVsync from the main thread to avoid race conditions with
+    // display power state.
+    postMessageAsync(new LambdaMessage(
+            [=]() NO_THREAD_SAFETY_ANALYSIS { setPrimaryVsyncEnabledInternal(enabled); }));
+}
+
+void SurfaceFlinger::setPrimaryVsyncEnabledInternal(bool enabled) {
+    ATRACE_CALL();
+
+    mHWCVsyncPendingState = enabled ? HWC2::Vsync::Enable : HWC2::Vsync::Disable;
+
     if (const auto displayId = getInternalDisplayIdLocked()) {
-        getHwComposer().setVsyncEnabled(*displayId,
-                                        enabled ? HWC2::Vsync::Enable : HWC2::Vsync::Disable);
+        sp<DisplayDevice> display = getDefaultDisplayDeviceLocked();
+        if (display && display->isPoweredOn()) {
+            setVsyncEnabledInHWC(*displayId, mHWCVsyncPendingState);
+        }
     }
 }
 
@@ -1642,10 +1693,26 @@
     return fence != Fence::NO_FENCE && (fence->getStatus() == Fence::Status::Unsignaled);
 }
 
+void SurfaceFlinger::populateExpectedPresentTime() NO_THREAD_SAFETY_ANALYSIS {
+    DisplayStatInfo stats;
+    mScheduler->getDisplayStatInfo(&stats);
+    const nsecs_t presentTime = mScheduler->getDispSyncExpectedPresentTime();
+    // Inflate the expected present time if we're targetting the next vsync.
+    mExpectedPresentTime =
+            mVsyncModulator.getOffsets().sf < mPhaseOffsets->getOffsetThresholdForNextVsync()
+            ? presentTime
+            : presentTime + stats.vsyncPeriod;
+}
+
 void SurfaceFlinger::onMessageReceived(int32_t what) NO_THREAD_SAFETY_ANALYSIS {
     ATRACE_CALL();
     switch (what) {
         case MessageQueue::INVALIDATE: {
+            // calculate the expected present time once and use the cached
+            // value throughout this frame to make sure all layers are
+            // seeing this same value.
+            populateExpectedPresentTime();
+
             bool frameMissed = previousFrameMissed();
             bool hwcFrameMissed = mHadDeviceComposition && frameMissed;
             bool gpuFrameMissed = mHadClientComposition && frameMissed;
@@ -1845,7 +1912,14 @@
             RenderIntent renderIntent;
             pickColorMode(displayDevice, &colorMode, &targetDataspace, &renderIntent);
             display->setColorMode(colorMode, targetDataspace, renderIntent);
+
+            if (isHdrColorMode(colorMode)) {
+                targetDataspace = Dataspace::UNKNOWN;
+            } else if (mColorSpaceAgnosticDataspace != Dataspace::UNKNOWN) {
+                targetDataspace = mColorSpaceAgnosticDataspace;
+            }
         }
+
         for (auto& layer : displayDevice->getVisibleLayersSortedByZ()) {
             if (layer->isHdrY410()) {
                 layer->forceClientComposition(displayDevice);
@@ -1872,9 +1946,7 @@
 
             const auto& displayState = display->getState();
             layer->setPerFrameData(displayDevice, displayState.transform, displayState.viewport,
-                                   displayDevice->getSupportedPerFrameMetadata(),
-                                   isHdrColorMode(displayState.colorMode) ? Dataspace::UNKNOWN
-                                                                          : targetDataspace);
+                                   displayDevice->getSupportedPerFrameMetadata(), targetDataspace);
         }
     }
 
@@ -3250,8 +3322,7 @@
     mDrawingState.traverseInZOrder([&](Layer* layer) {
         if (layer->hasReadyFrame()) {
             frameQueued = true;
-            nsecs_t expectedPresentTime;
-            expectedPresentTime = mScheduler->expectedPresentTime();
+            const nsecs_t expectedPresentTime = getExpectedPresentTime();
             if (layer->shouldPresentNow(expectedPresentTime)) {
                 mLayersWithQueuedFrames.push_back(layer);
             } else {
@@ -3648,7 +3719,7 @@
 
 bool SurfaceFlinger::transactionIsReadyToBeApplied(int64_t desiredPresentTime,
                                                    const Vector<ComposerState>& states) {
-    nsecs_t expectedPresentTime = mScheduler->expectedPresentTime();
+    nsecs_t expectedPresentTime = getExpectedPresentTime();
     // Do not present if the desiredPresentTime has not passed unless it is more than one second
     // in the future. We ignore timestamps more than 1 second in the future for stability reasons.
     if (desiredPresentTime >= 0 && desiredPresentTime >= expectedPresentTime &&
@@ -3772,6 +3843,7 @@
 
     if (uncacheBuffer.isValid()) {
         ClientCache::getInstance().erase(uncacheBuffer);
+        getRenderEngine().unbindExternalTextureBuffer(uncacheBuffer.id);
     }
 
     // If a synchronous transaction is explicitly requested without any changes, force a transaction
@@ -4126,9 +4198,18 @@
     bool bufferChanged = what & layer_state_t::eBufferChanged;
     bool cacheIdChanged = what & layer_state_t::eCachedBufferChanged;
     sp<GraphicBuffer> buffer;
-    if (bufferChanged && cacheIdChanged) {
-        ClientCache::getInstance().add(s.cachedBuffer, s.buffer);
+    if (bufferChanged && cacheIdChanged && s.buffer != nullptr) {
         buffer = s.buffer;
+        bool success = ClientCache::getInstance().add(s.cachedBuffer, s.buffer);
+        if (success) {
+            getRenderEngine().cacheExternalTextureBuffer(s.buffer);
+            success = ClientCache::getInstance()
+                              .registerErasedRecipient(s.cachedBuffer,
+                                                       wp<ClientCache::ErasedRecipient>(this));
+            if (!success) {
+                getRenderEngine().unbindExternalTextureBuffer(s.buffer->getId());
+            }
+        }
     } else if (cacheIdChanged) {
         buffer = ClientCache::getInstance().get(s.cachedBuffer);
     } else if (bufferChanged) {
@@ -4411,6 +4492,13 @@
             new LambdaMessage([this]() NO_THREAD_SAFETY_ANALYSIS { onInitializeDisplays(); }));
 }
 
+void SurfaceFlinger::setVsyncEnabledInHWC(DisplayId displayId, HWC2::Vsync enabled) {
+    if (mHWCVsyncState != enabled) {
+        getHwComposer().setVsyncEnabled(displayId, enabled);
+        mHWCVsyncState = enabled;
+    }
+}
+
 void SurfaceFlinger::setPowerModeInternal(const sp<DisplayDevice>& display, int mode) {
     if (display->isVirtual()) {
         ALOGE("%s: Invalid operation on virtual display", __FUNCTION__);
@@ -4437,6 +4525,7 @@
         // Turn on the display
         getHwComposer().setPowerMode(*displayId, mode);
         if (display->isPrimary() && mode != HWC_POWER_MODE_DOZE_SUSPEND) {
+            setVsyncEnabledInHWC(*displayId, mHWCVsyncPendingState);
             mScheduler->onScreenAcquired(mAppConnectionHandle);
             mScheduler->resyncToHardwareVsync(true, getVsyncPeriod());
         }
@@ -4462,6 +4551,9 @@
             mScheduler->onScreenReleased(mAppConnectionHandle);
         }
 
+        // Make sure HWVsync is disabled before turning off the display
+        setVsyncEnabledInHWC(*displayId, HWC2::Vsync::Disable);
+
         getHwComposer().setPowerMode(*displayId, mode);
         mVisibleRegionsDirty = true;
         // from this point on, SF will stop drawing on this display
@@ -4488,6 +4580,7 @@
     if (display->isPrimary()) {
         mTimeStats->setPowerMode(mode);
         mRefreshRateStats.setPowerMode(mode);
+        mScheduler->setDisplayPowerState(mode == HWC_POWER_MODE_NORMAL);
     }
 
     ALOGD("Finished setting power mode %d on display %s", mode, to_string(*displayId).c_str());
@@ -4652,6 +4745,16 @@
     StringAppendF(&result, "Scheduler enabled.");
     StringAppendF(&result, "+  Smart 90 for video detection: %s\n\n",
                   mUseSmart90ForVideo ? "on" : "off");
+    StringAppendF(&result, "Allowed Display Configs: ");
+    for (int32_t configId : mAllowedDisplayConfigs) {
+        for (auto refresh : mRefreshRateConfigs.getRefreshRates()) {
+            if (refresh.second && refresh.second->configId == configId) {
+                StringAppendF(&result, "%dHz, ", refresh.second->fps);
+            }
+        }
+    }
+    StringAppendF(&result, "(config override by backdoor: %s)\n\n",
+                  mDebugDisplayConfigSetByBackdoor ? "yes" : "no");
     mScheduler->dump(mAppConnectionHandle, result);
 }
 
@@ -4937,6 +5040,8 @@
 
     getRenderEngine().dump(result);
 
+    DebugEGLImageTracker::getInstance()->dump(result);
+
     if (const auto display = getDefaultDisplayDeviceLocked()) {
         display->getCompositionDisplay()->getState().undefinedRegion.dump(result,
                                                                           "undefinedRegion");
@@ -5350,7 +5455,12 @@
                 return NO_ERROR;
             }
             case 1023: { // Set native mode
+                int32_t colorMode;
+
                 mDisplayColorSetting = static_cast<DisplayColorSetting>(data.readInt32());
+                if (data.readInt32(&colorMode) == NO_ERROR) {
+                    mForceColorMode = static_cast<ColorMode>(colorMode);
+                }
                 invalidateHwcGeometry();
                 repaintEverything();
                 return NO_ERROR;
@@ -6065,8 +6175,20 @@
         return;
     }
 
+    const auto allowedDisplayConfigs = DisplayConfigs(allowedConfigs.begin(),
+                                                      allowedConfigs.end());
+    if (allowedDisplayConfigs == mAllowedDisplayConfigs) {
+        return;
+    }
+
     ALOGV("Updating allowed configs");
-    mAllowedDisplayConfigs = DisplayConfigs(allowedConfigs.begin(), allowedConfigs.end());
+    mAllowedDisplayConfigs = std::move(allowedDisplayConfigs);
+
+    // TODO(b/140204874): This hack triggers a notification that something has changed, so
+    // that listeners that care about a change in allowed configs can get the notification.
+    // Giving current ActiveConfig so that most other listeners would just drop the event
+    mScheduler->onConfigChanged(mAppConnectionHandle, display->getId()->value,
+                                display->getActiveConfig());
 
     // Set the highest allowed config by iterating backwards on available refresh rates
     const auto& refreshRates = mRefreshRateConfigs.getRefreshRates();
@@ -6146,6 +6268,10 @@
     return nullptr;
 }
 
+void SurfaceFlinger::bufferErased(const client_cache_t& clientCacheId) {
+    getRenderEngine().unbindExternalTextureBuffer(clientCacheId.id);
+}
+
 } // namespace android
 
 #if defined(__gl_h_)
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 63e74f5..f034832 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -170,9 +170,9 @@
 
 class SurfaceFlinger : public BnSurfaceComposer,
                        public PriorityDumper,
+                       public ClientCache::ErasedRecipient,
                        private IBinder::DeathRecipient,
-                       private HWC2::ComposerCallback
-{
+                       private HWC2::ComposerCallback {
 public:
     SurfaceFlingerBE& getBE() { return mBE; }
     const SurfaceFlingerBE& getBE() const { return mBE; }
@@ -293,11 +293,20 @@
     // TODO: this should be made accessible only to EventThread
     void setPrimaryVsyncEnabled(bool enabled);
 
+    // main thread function to enable/disable h/w composer event
+    void setPrimaryVsyncEnabledInternal(bool enabled);
+
     // called on the main thread by MessageQueue when an internal message
     // is received
     // TODO: this should be made accessible only to MessageQueue
     void onMessageReceived(int32_t what);
 
+    // populates the expected present time for this frame.
+    // When we are in negative offsets, we perform a correction so that the
+    // predicted vsync for the *next* frame is used instead.
+    void populateExpectedPresentTime();
+    nsecs_t getExpectedPresentTime() const { return mExpectedPresentTime; }
+
     // for debugging only
     // TODO: this should be made accessible only to HWComposer
     const Vector<sp<Layer>>& getLayerSortedByZForHwcDisplay(DisplayId displayId);
@@ -319,6 +328,9 @@
 
     sp<Layer> fromHandle(const sp<IBinder>& handle) REQUIRES(mStateLock);
 
+    // Inherit from ClientCache::ErasedRecipient
+    void bufferErased(const client_cache_t& clientCacheId) override;
+
 private:
     friend class BufferLayer;
     friend class BufferQueueLayer;
@@ -399,7 +411,9 @@
             const sp<IGraphicBufferProducer>& bufferProducer) const override;
     status_t getSupportedFrameTimestamps(std::vector<FrameEvent>* outSupported) const override;
     sp<IDisplayEventConnection> createDisplayEventConnection(
-            ISurfaceComposer::VsyncSource vsyncSource = eVsyncSourceApp) override;
+            ISurfaceComposer::VsyncSource vsyncSource = eVsyncSourceApp,
+            ISurfaceComposer::ConfigChanged configChanged =
+                    ISurfaceComposer::eConfigChangedSuppress) override;
     status_t captureScreen(const sp<IBinder>& displayToken, sp<GraphicBuffer>* outBuffer,
             bool& outCapturedSecureLayers, const ui::Dataspace reqDataspace,
             const ui::PixelFormat reqPixelFormat, Rect sourceCrop,
@@ -508,13 +522,15 @@
     // Sets the desired active config bit. It obtains the lock, and sets mDesiredActiveConfig.
     void setDesiredActiveConfig(const ActiveConfigInfo& info) REQUIRES(mStateLock);
     // Once HWC has returned the present fence, this sets the active config and a new refresh
-    // rate in SF. It also triggers HWC vsync.
+    // rate in SF.
     void setActiveConfigInternal() REQUIRES(mStateLock);
     // Active config is updated on INVALIDATE call in a state machine-like manner. When the
     // desired config was set, HWC needs to update the panel on the next refresh, and when
     // we receive the fence back, we know that the process was complete. It returns whether
     // we need to wait for the next invalidate
     bool performSetActiveConfig() REQUIRES(mStateLock);
+    // Called when active config is no longer is progress
+    void desiredActiveConfigChangeDone() REQUIRES(mStateLock);
     // called on the main thread in response to setPowerMode()
     void setPowerModeInternal(const sp<DisplayDevice>& display, int mode) REQUIRES(mStateLock);
 
@@ -833,6 +849,7 @@
     }
 
     bool previousFrameMissed();
+    void setVsyncEnabledInHWC(DisplayId displayId, HWC2::Vsync enabled);
 
     /*
      * Debugging & dumpsys
@@ -1106,6 +1123,7 @@
 
     ui::Dataspace mDefaultCompositionDataspace;
     ui::Dataspace mWideColorGamutCompositionDataspace;
+    ui::Dataspace mColorSpaceAgnosticDataspace;
 
     SurfaceFlingerBE mBE;
     std::unique_ptr<compositionengine::CompositionEngine> mCompositionEngine;
@@ -1170,6 +1188,12 @@
     // The Layer pointer is removed from the set when the destructor is called so there shouldn't
     // be any issues with a raw pointer referencing an invalid object.
     std::unordered_set<Layer*> mOffscreenLayers;
+
+    // Flags to capture the state of Vsync in HWC
+    HWC2::Vsync mHWCVsyncState = HWC2::Vsync::Disable;
+    HWC2::Vsync mHWCVsyncPendingState = HWC2::Vsync::Disable;
+
+    nsecs_t mExpectedPresentTime;
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/SurfaceFlingerProperties.cpp b/services/surfaceflinger/SurfaceFlingerProperties.cpp
index 2b33ba1..768074a 100644
--- a/services/surfaceflinger/SurfaceFlingerProperties.cpp
+++ b/services/surfaceflinger/SurfaceFlingerProperties.cpp
@@ -218,6 +218,14 @@
     return static_cast<int32_t>(defaultValue);
 }
 
+int64_t color_space_agnostic_dataspace(Dataspace defaultValue) {
+    auto temp = SurfaceFlingerProperties::color_space_agnostic_dataspace();
+    if (temp.has_value()) {
+        return *temp;
+    }
+    return static_cast<int64_t>(defaultValue);
+}
+
 int32_t set_idle_timer_ms(int32_t defaultValue) {
     auto temp = SurfaceFlingerProperties::set_idle_timer_ms();
     if (temp.has_value()) {
@@ -234,6 +242,14 @@
     return defaultValue;
 }
 
+int32_t set_display_power_timer_ms(int32_t defaultValue) {
+    auto temp = SurfaceFlingerProperties::set_display_power_timer_ms();
+    if (temp.has_value()) {
+        return *temp;
+    }
+    return defaultValue;
+}
+
 bool use_smart_90_for_video(bool defaultValue) {
     auto temp = SurfaceFlingerProperties::use_smart_90_for_video();
     if (temp.has_value()) {
diff --git a/services/surfaceflinger/SurfaceFlingerProperties.h b/services/surfaceflinger/SurfaceFlingerProperties.h
index 1964ccd..5f88322 100644
--- a/services/surfaceflinger/SurfaceFlingerProperties.h
+++ b/services/surfaceflinger/SurfaceFlingerProperties.h
@@ -70,10 +70,15 @@
 int32_t wcg_composition_pixel_format(
         android::hardware::graphics::common::V1_2::PixelFormat defaultValue);
 
+int64_t color_space_agnostic_dataspace(
+        android::hardware::graphics::common::V1_2::Dataspace defaultValue);
+
 int32_t set_idle_timer_ms(int32_t defaultValue);
 
 int32_t set_touch_timer_ms(int32_t defaultValue);
 
+int32_t set_display_power_timer_ms(int32_t defaultValue);
+
 bool use_smart_90_for_video(bool defaultValue);
 
 bool enable_protected_contents(bool defaultValue);
diff --git a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
index a8ec764..56ab4e3 100644
--- a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
+++ b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
@@ -251,6 +251,20 @@
     prop_name: "ro.surface_flinger.wcg_composition_pixel_format"
 }
 
+# colorSpaceAgnosticDataspace specifies the data space that
+# SurfaceFlinger expects for surfaces which are color space agnostic.
+# The variable works only when useColorManagement is specified. If
+# unspecified, the data space follows what SurfaceFlinger expects for
+# surfaces when useColorManagement is specified.
+
+prop {
+    api_name: "color_space_agnostic_dataspace"
+    type: Long
+    scope: System
+    access: Readonly
+    prop_name: "ro.surface_flinger.color_space_agnostic_dataspace"
+}
+
 # Return the native panel primary data. The data includes red, green,
 # blue and white. The primary format is CIE 1931 XYZ color space.
 # If unspecified, the primaries is sRGB gamut by default.
@@ -309,6 +323,18 @@
     prop_name: "ro.surface_flinger.set_touch_timer_ms"
 }
 
+# setDisplayPowerTimerMs indicates what is considered a timeout in milliseconds for Scheduler.
+# This value is used by the Scheduler to trigger display power inactivity callbacks that will
+# keep the display in peak refresh rate as long as display power is not in normal mode.
+# Setting this property to 0 means there is no timer.
+prop {
+    api_name: "set_display_power_timer_ms"
+    type: Integer
+    scope: System
+    access: Readonly
+    prop_name: "ro.surface_flinger.set_display_power_timer_ms"
+}
+
 # useSmart90ForVideo indicates whether Scheduler should detect content FPS, and try to adjust the
 # screen refresh rate based on that.
 prop {
diff --git a/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-current.txt b/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-current.txt
index 0611684..b66e56e 100644
--- a/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-current.txt
+++ b/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-current.txt
@@ -1,6 +1,11 @@
 props {
   module: "android.sysprop.SurfaceFlingerProperties"
   prop {
+    api_name: "color_space_agnostic_dataspace"
+    type: Long
+    prop_name: "ro.surface_flinger.color_space_agnostic_dataspace"
+  }
+  prop {
     api_name: "default_composition_dataspace"
     type: Long
     prop_name: "ro.surface_flinger.default_composition_dataspace"
@@ -72,6 +77,11 @@
     prop_name: "ro.surface_flinger.running_without_sync_framework"
   }
   prop {
+    api_name: "set_display_power_timer_ms"
+    type: Integer
+    prop_name: "ro.surface_flinger.set_display_power_timer_ms"
+  }
+  prop {
     api_name: "set_idle_timer_ms"
     type: Integer
     prop_name: "ro.surface_flinger.set_idle_timer_ms"
diff --git a/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-latest.txt b/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-latest.txt
index 0611684..b66e56e 100644
--- a/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-latest.txt
+++ b/services/surfaceflinger/sysprop/api/SurfaceFlingerProperties-latest.txt
@@ -1,6 +1,11 @@
 props {
   module: "android.sysprop.SurfaceFlingerProperties"
   prop {
+    api_name: "color_space_agnostic_dataspace"
+    type: Long
+    prop_name: "ro.surface_flinger.color_space_agnostic_dataspace"
+  }
+  prop {
     api_name: "default_composition_dataspace"
     type: Long
     prop_name: "ro.surface_flinger.default_composition_dataspace"
@@ -72,6 +77,11 @@
     prop_name: "ro.surface_flinger.running_without_sync_framework"
   }
   prop {
+    api_name: "set_display_power_timer_ms"
+    type: Integer
+    prop_name: "ro.surface_flinger.set_display_power_timer_ms"
+  }
+  prop {
     api_name: "set_idle_timer_ms"
     type: Integer
     prop_name: "ro.surface_flinger.set_idle_timer_ms"
diff --git a/services/surfaceflinger/tests/Transaction_test.cpp b/services/surfaceflinger/tests/Transaction_test.cpp
index d5f6534..c93e15e 100644
--- a/services/surfaceflinger/tests/Transaction_test.cpp
+++ b/services/surfaceflinger/tests/Transaction_test.cpp
@@ -28,6 +28,7 @@
 
 #include <binder/ProcessState.h>
 #include <gui/BufferItemConsumer.h>
+#include <gui/IProducerListener.h>
 #include <gui/ISurfaceComposer.h>
 #include <gui/LayerState.h>
 #include <gui/Surface.h>
@@ -6059,4 +6060,97 @@
     }
 }
 
+// This test ensures that when we drop an app buffer in SurfaceFlinger, we merge
+// the dropped buffer's damage region into the next buffer's damage region. If
+// we don't do this, we'll report an incorrect damage region to hardware
+// composer, resulting in broken rendering. This test checks the BufferQueue
+// case.
+//
+// Unfortunately, we don't currently have a way to inspect the damage region
+// SurfaceFlinger sends to hardware composer from a test, so this test requires
+// the dev to manually watch the device's screen during the test to spot broken
+// rendering. Because the results can't be automatically verified, this test is
+// marked disabled.
+TEST_F(LayerTransactionTest, DISABLED_BufferQueueLayerMergeDamageRegionWhenDroppingBuffers) {
+    const int width = mDisplayWidth;
+    const int height = mDisplayHeight;
+    sp<SurfaceControl> layer;
+    ASSERT_NO_FATAL_FAILURE(layer = createLayer("test", width, height));
+    const auto producer = layer->getIGraphicBufferProducer();
+    const sp<IProducerListener> dummyListener(new DummyProducerListener);
+    IGraphicBufferProducer::QueueBufferOutput queueBufferOutput;
+    ASSERT_EQ(OK,
+              producer->connect(dummyListener, NATIVE_WINDOW_API_CPU, true, &queueBufferOutput));
+
+    std::map<int, sp<GraphicBuffer>> slotMap;
+    auto slotToBuffer = [&](int slot, sp<GraphicBuffer>* buf) {
+        ASSERT_NE(nullptr, buf);
+        const auto iter = slotMap.find(slot);
+        ASSERT_NE(slotMap.end(), iter);
+        *buf = iter->second;
+    };
+
+    auto dequeue = [&](int* outSlot) {
+        ASSERT_NE(nullptr, outSlot);
+        *outSlot = -1;
+        int slot;
+        sp<Fence> fence;
+        uint64_t age;
+        FrameEventHistoryDelta timestamps;
+        const status_t dequeueResult =
+                producer->dequeueBuffer(&slot, &fence, width, height, PIXEL_FORMAT_RGBA_8888,
+                                        GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN,
+                                        &age, &timestamps);
+        if (dequeueResult == IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION) {
+            sp<GraphicBuffer> newBuf;
+            ASSERT_EQ(OK, producer->requestBuffer(slot, &newBuf));
+            ASSERT_NE(nullptr, newBuf.get());
+            slotMap[slot] = newBuf;
+        } else {
+            ASSERT_EQ(OK, dequeueResult);
+        }
+        *outSlot = slot;
+    };
+
+    auto queue = [&](int slot, const Region& damage, nsecs_t displayTime) {
+        IGraphicBufferProducer::QueueBufferInput input(
+                /*timestamp=*/displayTime, /*isAutoTimestamp=*/false, HAL_DATASPACE_UNKNOWN,
+                /*crop=*/Rect::EMPTY_RECT, NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW,
+                /*transform=*/0, Fence::NO_FENCE);
+        input.setSurfaceDamage(damage);
+        IGraphicBufferProducer::QueueBufferOutput output;
+        ASSERT_EQ(OK, producer->queueBuffer(slot, input, &output));
+    };
+
+    auto fillAndPostBuffers = [&](const Color& color) {
+        int slot1;
+        ASSERT_NO_FATAL_FAILURE(dequeue(&slot1));
+        int slot2;
+        ASSERT_NO_FATAL_FAILURE(dequeue(&slot2));
+
+        sp<GraphicBuffer> buf1;
+        ASSERT_NO_FATAL_FAILURE(slotToBuffer(slot1, &buf1));
+        sp<GraphicBuffer> buf2;
+        ASSERT_NO_FATAL_FAILURE(slotToBuffer(slot2, &buf2));
+        fillGraphicBufferColor(buf1, Rect(width, height), color);
+        fillGraphicBufferColor(buf2, Rect(width, height), color);
+
+        const auto displayTime = systemTime() + milliseconds_to_nanoseconds(100);
+        ASSERT_NO_FATAL_FAILURE(queue(slot1, Region::INVALID_REGION, displayTime));
+        ASSERT_NO_FATAL_FAILURE(
+                queue(slot2, Region(Rect(width / 3, height / 3, 2 * width / 3, 2 * height / 3)),
+                      displayTime));
+    };
+
+    const auto startTime = systemTime();
+    const std::array<Color, 3> colors = {Color::RED, Color::GREEN, Color::BLUE};
+    int colorIndex = 0;
+    while (nanoseconds_to_seconds(systemTime() - startTime) < 10) {
+        ASSERT_NO_FATAL_FAILURE(fillAndPostBuffers(colors[colorIndex++ % colors.size()]));
+        std::this_thread::sleep_for(1s);
+    }
+
+    ASSERT_EQ(OK, producer->disconnect(NATIVE_WINDOW_API_CPU));
+}
+
 } // namespace android
diff --git a/services/surfaceflinger/tests/unittests/DispSyncSourceTest.cpp b/services/surfaceflinger/tests/unittests/DispSyncSourceTest.cpp
index 2e705da..0aa8cf5 100644
--- a/services/surfaceflinger/tests/unittests/DispSyncSourceTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DispSyncSourceTest.cpp
@@ -51,6 +51,7 @@
     AsyncCallRecorder<void (*)(nsecs_t)> mVSyncEventCallRecorder;
 
     static constexpr std::chrono::nanoseconds mPhaseOffset = 6ms;
+    static constexpr std::chrono::nanoseconds mOffsetThresholdForNextVsync = 16ms;
     static constexpr int mIterations = 100;
 };
 
@@ -78,7 +79,8 @@
 
 void DispSyncSourceTest::createDispSyncSource() {
     createDispSync();
-    mDispSyncSource = std::make_unique<DispSyncSource>(mDispSync.get(), mPhaseOffset.count(), true,
+    mDispSyncSource = std::make_unique<DispSyncSource>(mDispSync.get(), mPhaseOffset.count(),
+                                                       mOffsetThresholdForNextVsync.count(), true,
                                                        "DispSyncSourceTest");
     mDispSyncSource->setCallback(this);
 }
diff --git a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
index ea908a9..dbd9b84 100644
--- a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
+++ b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
@@ -55,8 +55,9 @@
     class MockEventThreadConnection : public EventThreadConnection {
     public:
         MockEventThreadConnection(android::impl::EventThread* eventThread,
-                                  ResyncCallback&& resyncCallback)
-              : EventThreadConnection(eventThread, std::move(resyncCallback)) {}
+                                  ResyncCallback&& resyncCallback,
+                                  ISurfaceComposer::ConfigChanged configChanged)
+              : EventThreadConnection(eventThread, std::move(resyncCallback), configChanged) {}
         MOCK_METHOD1(postEvent, status_t(const DisplayEventReceiver::Event& event));
     };
 
@@ -67,7 +68,8 @@
     ~EventThreadTest() override;
 
     void createThread();
-    sp<MockEventThreadConnection> createConnection(ConnectionEventRecorder& recorder);
+    sp<MockEventThreadConnection> createConnection(ConnectionEventRecorder& recorder,
+                                                   ISurfaceComposer::ConfigChanged configChanged);
 
     void expectVSyncSetEnabledCallReceived(bool expectedState);
     void expectVSyncSetPhaseOffsetCallReceived(nsecs_t expectedPhaseOffset);
@@ -110,7 +112,8 @@
             .WillRepeatedly(Invoke(mVSyncSetPhaseOffsetCallRecorder.getInvocable()));
 
     createThread();
-    mConnection = createConnection(mConnectionEventCallRecorder);
+    mConnection = createConnection(mConnectionEventCallRecorder,
+                                   ISurfaceComposer::eConfigChangedDispatch);
 
     // A display must be connected for VSYNC events to be delivered.
     mThread->onHotplugReceived(INTERNAL_DISPLAY_ID, true);
@@ -138,9 +141,10 @@
 }
 
 sp<EventThreadTest::MockEventThreadConnection> EventThreadTest::createConnection(
-        ConnectionEventRecorder& recorder) {
+        ConnectionEventRecorder& recorder, ISurfaceComposer::ConfigChanged configChanged) {
     sp<MockEventThreadConnection> connection =
-            new MockEventThreadConnection(mThread.get(), mResyncCallRecorder.getInvocable());
+            new MockEventThreadConnection(mThread.get(), mResyncCallRecorder.getInvocable(),
+                                          configChanged);
     EXPECT_CALL(*connection, postEvent(_)).WillRepeatedly(Invoke(recorder.getInvocable()));
     return connection;
 }
@@ -267,7 +271,9 @@
 TEST_F(EventThreadTest, setVsyncRateZeroPostsNoVSyncEventsToThatConnection) {
     // Create a first connection, register it, and request a vsync rate of zero.
     ConnectionEventRecorder firstConnectionEventRecorder{0};
-    sp<MockEventThreadConnection> firstConnection = createConnection(firstConnectionEventRecorder);
+    sp<MockEventThreadConnection> firstConnection =
+            createConnection(firstConnectionEventRecorder,
+                             ISurfaceComposer::eConfigChangedSuppress);
     mThread->setVsyncRate(0, firstConnection);
 
     // By itself, this should not enable vsync events
@@ -277,7 +283,8 @@
     // However if there is another connection which wants events at a nonzero rate.....
     ConnectionEventRecorder secondConnectionEventRecorder{0};
     sp<MockEventThreadConnection> secondConnection =
-            createConnection(secondConnectionEventRecorder);
+            createConnection(secondConnectionEventRecorder,
+                             ISurfaceComposer::eConfigChangedSuppress);
     mThread->setVsyncRate(1, secondConnection);
 
     // EventThread should enable vsync callbacks.
@@ -363,7 +370,9 @@
 
 TEST_F(EventThreadTest, connectionsRemovedIfEventDeliveryError) {
     ConnectionEventRecorder errorConnectionEventRecorder{NO_MEMORY};
-    sp<MockEventThreadConnection> errorConnection = createConnection(errorConnectionEventRecorder);
+    sp<MockEventThreadConnection> errorConnection =
+            createConnection(errorConnectionEventRecorder,
+                             ISurfaceComposer::eConfigChangedSuppress);
     mThread->setVsyncRate(1, errorConnection);
 
     // EventThread should enable vsync callbacks.
@@ -387,7 +396,9 @@
 
 TEST_F(EventThreadTest, eventsDroppedIfNonfatalEventDeliveryError) {
     ConnectionEventRecorder errorConnectionEventRecorder{WOULD_BLOCK};
-    sp<MockEventThreadConnection> errorConnection = createConnection(errorConnectionEventRecorder);
+    sp<MockEventThreadConnection> errorConnection =
+            createConnection(errorConnectionEventRecorder,
+                             ISurfaceComposer::eConfigChangedSuppress);
     mThread->setVsyncRate(1, errorConnection);
 
     // EventThread should enable vsync callbacks.
@@ -449,5 +460,18 @@
     expectConfigChangedEventReceivedByConnection(DISPLAY_ID_64BIT, 7);
 }
 
+TEST_F(EventThreadTest, suppressConfigChanged) {
+    ConnectionEventRecorder suppressConnectionEventRecorder{0};
+    sp<MockEventThreadConnection> suppressConnection =
+            createConnection(suppressConnectionEventRecorder,
+                             ISurfaceComposer::eConfigChangedSuppress);
+
+    mThread->onConfigChanged(INTERNAL_DISPLAY_ID, 9);
+    expectConfigChangedEventReceivedByConnection(INTERNAL_DISPLAY_ID, 9);
+
+    auto args = suppressConnectionEventRecorder.waitForCall();
+    ASSERT_FALSE(args.has_value());
+}
+
 } // namespace
 } // namespace android
diff --git a/services/surfaceflinger/tests/unittests/FakePhaseOffsets.h b/services/surfaceflinger/tests/unittests/FakePhaseOffsets.h
index 96121bb..1d75011 100644
--- a/services/surfaceflinger/tests/unittests/FakePhaseOffsets.h
+++ b/services/surfaceflinger/tests/unittests/FakePhaseOffsets.h
@@ -23,6 +23,8 @@
 namespace android {
 namespace scheduler {
 
+using RefreshRateType = RefreshRateConfigs::RefreshRateType;
+
 class FakePhaseOffsets : public android::scheduler::PhaseOffsets {
     nsecs_t FAKE_PHASE_OFFSET_NS = 0;
 
@@ -34,20 +36,20 @@
     nsecs_t getCurrentSfOffset() override { return FAKE_PHASE_OFFSET_NS; }
 
     PhaseOffsets::Offsets getOffsetsForRefreshRate(
-            RefreshRateConfigs::RefreshRateType /*refreshRateType*/) const override {
+            RefreshRateType /*refreshRateType*/) const override {
         return getCurrentOffsets();
     }
 
     // Returns early, early GL, and late offsets for Apps and SF.
     PhaseOffsets::Offsets getCurrentOffsets() const override {
-        return Offsets{{FAKE_PHASE_OFFSET_NS, FAKE_PHASE_OFFSET_NS},
-                       {FAKE_PHASE_OFFSET_NS, FAKE_PHASE_OFFSET_NS},
-                       {FAKE_PHASE_OFFSET_NS, FAKE_PHASE_OFFSET_NS}};
+        return Offsets{{RefreshRateType::DEFAULT, FAKE_PHASE_OFFSET_NS, FAKE_PHASE_OFFSET_NS},
+                       {RefreshRateType::DEFAULT, FAKE_PHASE_OFFSET_NS, FAKE_PHASE_OFFSET_NS},
+                       {RefreshRateType::DEFAULT, FAKE_PHASE_OFFSET_NS, FAKE_PHASE_OFFSET_NS}};
     }
 
     // This function should be called when the device is switching between different
     // refresh rates, to properly update the offsets.
-    void setRefreshRateType(RefreshRateConfigs::RefreshRateType /*refreshRateType*/) override {}
+    void setRefreshRateType(RefreshRateType /*refreshRateType*/) override {}
 
     nsecs_t getOffsetThresholdForNextVsync() const override { return FAKE_PHASE_OFFSET_NS; }
 
@@ -56,4 +58,4 @@
 };
 
 } // namespace scheduler
-} // namespace android
\ No newline at end of file
+} // namespace android
diff --git a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
index 2b1dfa8..8e7440c 100644
--- a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
+++ b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
@@ -25,7 +25,17 @@
 protected:
     std::unique_ptr<LayerHistory> mLayerHistory;
 
+    static constexpr float MIN_REFRESH_RATE = 30.f;
     static constexpr float MAX_REFRESH_RATE = 90.f;
+    static constexpr auto RELEVANT_FRAME_THRESHOLD = 90u;
+    static constexpr uint64_t THIRTY_FPS_INTERVAL = 33'333'333;
+
+    void forceRelevancy(const std::unique_ptr<LayerHistory::LayerHandle>& testLayer) {
+        mLayerHistory->setVisibility(testLayer, true);
+        for (auto i = 0u; i < RELEVANT_FRAME_THRESHOLD; i++) {
+            mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
+        }
+    };
 };
 
 LayerHistoryTest::LayerHistoryTest() {
@@ -36,31 +46,25 @@
 namespace {
 TEST_F(LayerHistoryTest, oneLayer) {
     std::unique_ptr<LayerHistory::LayerHandle> testLayer =
-            mLayerHistory->createLayer("TestLayer", MAX_REFRESH_RATE);
+            mLayerHistory->createLayer("TestLayer", MIN_REFRESH_RATE, MAX_REFRESH_RATE);
     mLayerHistory->setVisibility(testLayer, true);
+    for (auto i = 0u; i < RELEVANT_FRAME_THRESHOLD; i++) {
+        EXPECT_FLOAT_EQ(0.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
+        mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
+    }
 
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    EXPECT_FLOAT_EQ(0.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
-
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    // This is still 0, because the layer is not considered recently active if it
-    // has been present in less than 10 frames.
-    EXPECT_FLOAT_EQ(0.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    // This should be MAX_REFRESH_RATE as we have more than 10 samples
-    EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
+    // Add a few more. This time we should get MAX refresh rate as the layer
+    // becomes relevant
+    static constexpr auto A_FEW = 10;
+    for (auto i = 0u; i < A_FEW; i++) {
+        EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
+        mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
+    }
 }
 
 TEST_F(LayerHistoryTest, oneHDRLayer) {
     std::unique_ptr<LayerHistory::LayerHandle> testLayer =
-            mLayerHistory->createLayer("TestHDRLayer", MAX_REFRESH_RATE);
+            mLayerHistory->createLayer("TestHDRLayer", MIN_REFRESH_RATE, MAX_REFRESH_RATE);
     mLayerHistory->setVisibility(testLayer, true);
 
     mLayerHistory->insert(testLayer, 0, true /*isHDR*/);
@@ -74,12 +78,13 @@
 
 TEST_F(LayerHistoryTest, explicitTimestamp) {
     std::unique_ptr<LayerHistory::LayerHandle> test30FpsLayer =
-            mLayerHistory->createLayer("30FpsLayer", MAX_REFRESH_RATE);
+            mLayerHistory->createLayer("30FpsLayer", MIN_REFRESH_RATE, MAX_REFRESH_RATE);
     mLayerHistory->setVisibility(test30FpsLayer, true);
 
     nsecs_t startTime = systemTime();
-    for (int i = 0; i < 31; i++) {
-        mLayerHistory->insert(test30FpsLayer, startTime + (i * 33333333), false /*isHDR*/);
+    for (int i = 0; i < RELEVANT_FRAME_THRESHOLD; i++) {
+        mLayerHistory->insert(test30FpsLayer, startTime + (i * THIRTY_FPS_INTERVAL),
+                              false /*isHDR*/);
     }
 
     EXPECT_FLOAT_EQ(30.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
@@ -87,29 +92,31 @@
 
 TEST_F(LayerHistoryTest, multipleLayers) {
     std::unique_ptr<LayerHistory::LayerHandle> testLayer =
-            mLayerHistory->createLayer("TestLayer", MAX_REFRESH_RATE);
+            mLayerHistory->createLayer("TestLayer", MIN_REFRESH_RATE, MAX_REFRESH_RATE);
     mLayerHistory->setVisibility(testLayer, true);
     std::unique_ptr<LayerHistory::LayerHandle> test30FpsLayer =
-            mLayerHistory->createLayer("30FpsLayer", MAX_REFRESH_RATE);
+            mLayerHistory->createLayer("30FpsLayer", MIN_REFRESH_RATE, MAX_REFRESH_RATE);
     mLayerHistory->setVisibility(test30FpsLayer, true);
     std::unique_ptr<LayerHistory::LayerHandle> testLayer2 =
-            mLayerHistory->createLayer("TestLayer2", MAX_REFRESH_RATE);
+            mLayerHistory->createLayer("TestLayer2", MIN_REFRESH_RATE, MAX_REFRESH_RATE);
     mLayerHistory->setVisibility(testLayer2, true);
 
     nsecs_t startTime = systemTime();
-    for (int i = 0; i < 10; i++) {
+    for (int i = 0; i < RELEVANT_FRAME_THRESHOLD; i++) {
         mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
     }
     EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
 
     startTime = systemTime();
-    for (int i = 0; i < 10; i++) {
-        mLayerHistory->insert(test30FpsLayer, startTime + (i * 33333333), false /*isHDR*/);
+    for (int i = 0; i < RELEVANT_FRAME_THRESHOLD; i++) {
+        mLayerHistory->insert(test30FpsLayer, startTime + (i * THIRTY_FPS_INTERVAL),
+                              false /*isHDR*/);
     }
     EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
 
-    for (int i = 10; i < 30; i++) {
-        mLayerHistory->insert(test30FpsLayer, startTime + (i * 33333333), false /*isHDR*/);
+    for (int i = 10; i < RELEVANT_FRAME_THRESHOLD; i++) {
+        mLayerHistory->insert(test30FpsLayer, startTime + (i * THIRTY_FPS_INTERVAL),
+                              false /*isHDR*/);
     }
     EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
 
@@ -119,10 +126,12 @@
         mLayerHistory->insert(testLayer2, 0, false /*isHDR*/);
     }
     EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
-    // After 100 ms frames become obsolete.
-    std::this_thread::sleep_for(std::chrono::milliseconds(500));
-    // Insert the 31st frame.
-    mLayerHistory->insert(test30FpsLayer, startTime + (30 * 33333333), false /*isHDR*/);
+    // After 1200 ms frames become obsolete.
+    std::this_thread::sleep_for(std::chrono::milliseconds(1500));
+
+    mLayerHistory->insert(test30FpsLayer,
+                          startTime + (RELEVANT_FRAME_THRESHOLD * THIRTY_FPS_INTERVAL),
+                          false /*isHDR*/);
     EXPECT_FLOAT_EQ(30.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
 }
 
diff --git a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
index 1f8b111..740115e 100644
--- a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
@@ -25,7 +25,8 @@
     class MockEventThreadConnection : public android::EventThreadConnection {
     public:
         explicit MockEventThreadConnection(EventThread* eventThread)
-              : EventThreadConnection(eventThread, ResyncCallback()) {}
+              : EventThreadConnection(eventThread, ResyncCallback(),
+                                      ISurfaceComposer::eConfigChangedSuppress) {}
         ~MockEventThreadConnection() = default;
 
         MOCK_METHOD1(stealReceiveChannel, status_t(gui::BitTube* outChannel));
@@ -47,7 +48,7 @@
 
         std::unique_ptr<EventThread> makeEventThread(
                 const char* /* connectionName */, DispSync* /* dispSync */,
-                nsecs_t /* phaseOffsetNs */,
+                nsecs_t /* phaseOffsetNs */, nsecs_t /* offsetThresholdForNextVsync */,
                 impl::EventThread::InterceptVSyncsCallback /* interceptCallback */) override {
             return std::move(mEventThread);
         }
@@ -81,10 +82,10 @@
 
     // createConnection call to scheduler makes a createEventConnection call to EventThread. Make
     // sure that call gets executed and returns an EventThread::Connection object.
-    EXPECT_CALL(*mEventThread, createEventConnection(_))
+    EXPECT_CALL(*mEventThread, createEventConnection(_, _))
             .WillRepeatedly(Return(mEventThreadConnection));
 
-    mConnectionHandle = mScheduler->createConnection("appConnection", 16, ResyncCallback(),
+    mConnectionHandle = mScheduler->createConnection("appConnection", 16, 16, ResyncCallback(),
                                                      impl::EventThread::InterceptVSyncsCallback());
     EXPECT_TRUE(mConnectionHandle != nullptr);
 }
@@ -105,7 +106,10 @@
     // exceptions, just gracefully continues.
     sp<IDisplayEventConnection> returnedValue;
     ASSERT_NO_FATAL_FAILURE(
-            returnedValue = mScheduler->createDisplayEventConnection(nullptr, ResyncCallback()));
+            returnedValue =
+                    mScheduler->createDisplayEventConnection(nullptr, ResyncCallback(),
+                                                             ISurfaceComposer::
+                                                                     eConfigChangedSuppress));
     EXPECT_TRUE(returnedValue == nullptr);
     EXPECT_TRUE(mScheduler->getEventThread(nullptr) == nullptr);
     EXPECT_TRUE(mScheduler->getEventConnection(nullptr) == nullptr);
@@ -126,7 +130,9 @@
     sp<IDisplayEventConnection> returnedValue;
     ASSERT_NO_FATAL_FAILURE(
             returnedValue =
-                    mScheduler->createDisplayEventConnection(connectionHandle, ResyncCallback()));
+                    mScheduler->createDisplayEventConnection(connectionHandle, ResyncCallback(),
+                                                             ISurfaceComposer::
+                                                                     eConfigChangedSuppress));
     EXPECT_TRUE(returnedValue == nullptr);
     EXPECT_TRUE(mScheduler->getEventThread(connectionHandle) == nullptr);
     EXPECT_TRUE(mScheduler->getEventConnection(connectionHandle) == nullptr);
@@ -155,7 +161,9 @@
     sp<IDisplayEventConnection> returnedValue;
     ASSERT_NO_FATAL_FAILURE(
             returnedValue =
-                    mScheduler->createDisplayEventConnection(mConnectionHandle, ResyncCallback()));
+                    mScheduler->createDisplayEventConnection(mConnectionHandle, ResyncCallback(),
+                                                             ISurfaceComposer::
+                                                                     eConfigChangedSuppress));
     EXPECT_TRUE(returnedValue != nullptr);
     ASSERT_EQ(returnedValue, mEventThreadConnection);
 
diff --git a/services/surfaceflinger/tests/unittests/TestableScheduler.h b/services/surfaceflinger/tests/unittests/TestableScheduler.h
index c3d2b8d..cb6980e 100644
--- a/services/surfaceflinger/tests/unittests/TestableScheduler.h
+++ b/services/surfaceflinger/tests/unittests/TestableScheduler.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <gmock/gmock.h>
+#include <gui/ISurfaceComposer.h>
 
 #include "Scheduler/EventThread.h"
 #include "Scheduler/RefreshRateConfigs.h"
@@ -34,7 +35,8 @@
     // Scheduler::Connection. This allows plugging in mock::EventThread.
     sp<Scheduler::ConnectionHandle> addConnection(std::unique_ptr<EventThread> eventThread) {
         sp<EventThreadConnection> eventThreadConnection =
-                new EventThreadConnection(eventThread.get(), ResyncCallback());
+                new EventThreadConnection(eventThread.get(), ResyncCallback(),
+                                          ISurfaceComposer::eConfigChangedSuppress);
         const int64_t id = sNextId++;
         mConnections.emplace(id,
                              std::make_unique<Scheduler::Connection>(new ConnectionHandle(id),
diff --git a/services/surfaceflinger/tests/unittests/mock/MockDispSync.h b/services/surfaceflinger/tests/unittests/mock/MockDispSync.h
index 12a349d..9ca116d 100644
--- a/services/surfaceflinger/tests/unittests/mock/MockDispSync.h
+++ b/services/surfaceflinger/tests/unittests/mock/MockDispSync.h
@@ -35,6 +35,7 @@
     MOCK_METHOD0(endResync, void());
     MOCK_METHOD1(setPeriod, void(nsecs_t));
     MOCK_METHOD0(getPeriod, nsecs_t());
+    MOCK_METHOD0(getIntendedPeriod, nsecs_t());
     MOCK_METHOD1(setRefreshSkipCount, void(int));
     MOCK_CONST_METHOD1(computeNextRefresh, nsecs_t(int));
     MOCK_METHOD1(setIgnorePresentFences, void(bool));
diff --git a/services/surfaceflinger/tests/unittests/mock/MockEventThread.h b/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
index 5b5f8e7..ed35ebf 100644
--- a/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
+++ b/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
@@ -28,7 +28,8 @@
     EventThread();
     ~EventThread() override;
 
-    MOCK_CONST_METHOD1(createEventConnection, sp<EventThreadConnection>(ResyncCallback));
+    MOCK_CONST_METHOD2(createEventConnection,
+                       sp<EventThreadConnection>(ResyncCallback, ISurfaceComposer::ConfigChanged));
     MOCK_METHOD0(onScreenReleased, void());
     MOCK_METHOD0(onScreenAcquired, void());
     MOCK_METHOD2(onHotplugReceived, void(PhysicalDisplayId, bool));