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/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/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 6c9d81a..e487792 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/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/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/BufferQueueLayer.cpp b/services/surfaceflinger/BufferQueueLayer.cpp
index bd0b55f..d685366 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;
diff --git a/services/surfaceflinger/BufferStateLayer.cpp b/services/surfaceflinger/BufferStateLayer.cpp
index 05c721f..2abc1a7 100644
--- a/services/surfaceflinger/BufferStateLayer.cpp
+++ b/services/surfaceflinger/BufferStateLayer.cpp
@@ -50,12 +50,6 @@
     mOverrideScalingMode = NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW;
     mCurrentState.dataspace = ui::Dataspace::V0_SRGB;
 }
-BufferStateLayer::~BufferStateLayer() {
-    if (mActiveBuffer != nullptr) {
-        auto& engine(mFlinger->getRenderEngine());
-        engine.unbindExternalTextureBuffer(mActiveBuffer->getId());
-    }
-}
 
 // -----------------------------------------------------------------------
 // Interface implementation for Layer
@@ -380,7 +374,7 @@
         return true;
     }
 
-    return mDesiredPresentTime <= mFlinger->mScheduler->expectedPresentTime();
+    return mDesiredPresentTime <= mFlinger->getExpectedPresentTime();
 }
 
 nsecs_t BufferStateLayer::getDesiredPresentTime() {
@@ -571,11 +565,6 @@
         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;
@@ -621,6 +610,10 @@
     }
 }
 
+void BufferStateLayer::bufferErased(const client_cache_t& clientCacheId) {
+    mFlinger->getRenderEngine().unbindExternalTextureBuffer(clientCacheId.id);
+}
+
 void BufferStateLayer::HwcSlotGenerator::bufferErased(const client_cache_t& clientCacheId) {
     std::lock_guard lock(mMutex);
     if (!clientCacheId.isValid()) {
diff --git a/services/surfaceflinger/BufferStateLayer.h b/services/surfaceflinger/BufferStateLayer.h
index 4e2bc45..db8ae0d 100644
--- a/services/surfaceflinger/BufferStateLayer.h
+++ b/services/surfaceflinger/BufferStateLayer.h
@@ -34,7 +34,6 @@
 class BufferStateLayer : public BufferLayer {
 public:
     explicit BufferStateLayer(const LayerCreationArgs&);
-    ~BufferStateLayer() override;
 
     // -----------------------------------------------------------------------
     // Interface implementation for Layer
@@ -103,6 +102,9 @@
     bool fenceHasSignaled() const override;
     bool framePresentTimeIsCurrent() const override;
 
+    // Inherit from ClientCache::ErasedRecipient
+    void bufferErased(const client_cache_t& clientCacheId) override;
+
 private:
     nsecs_t getDesiredPresentTime() override;
     std::shared_ptr<FenceTime> getCurrentFenceTime() const override;
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.h b/services/surfaceflinger/Layer.h
index 5c55111..6db6beb 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 {
@@ -94,7 +93,7 @@
     LayerMetadata metadata;
 };
 
-class Layer : public virtual compositionengine::LayerFE {
+class Layer : public virtual compositionengine::LayerFE, public ClientCache::ErasedRecipient {
     static std::atomic<int32_t> sSequence;
 
 public:
@@ -701,6 +700,9 @@
     compositionengine::OutputLayer* findOutputLayerForDisplay(
             const sp<const DisplayDevice>& display) const;
 
+    // Inherit from ClientCache::ErasedRecipient
+    void bufferErased(const client_cache_t& /*clientCacheId*/) override {}
+
 protected:
     // constant
     sp<SurfaceFlinger> mFlinger;
diff --git a/services/surfaceflinger/RegionSamplingThread.cpp b/services/surfaceflinger/RegionSamplingThread.cpp
index 66906e9..72bbf5d 100644
--- a/services/surfaceflinger/RegionSamplingThread.cpp
+++ b/services/surfaceflinger/RegionSamplingThread.cpp
@@ -258,7 +258,7 @@
 
 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 +293,10 @@
         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 +342,19 @@
     }
 
     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/Scheduler/DispSync.cpp b/services/surfaceflinger/Scheduler/DispSync.cpp
index cd6fa41..83fd42b 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() {
@@ -764,6 +770,9 @@
     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..026b557 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 +69,17 @@
 
 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;
     mPhaseOffset = phaseOffset;
+    tracePhaseOffset();
 
     // If we're not enabled, we don't need to mess with the listeners
     if (!mEnabled) {
@@ -92,11 +98,11 @@
     {
         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 +110,14 @@
     }
 }
 
-} // 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..beddb9b 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;
@@ -38,10 +39,16 @@
     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;
+    if (timeDiff > OBSOLETE_TIME_EPSILON_NS.count()) return;
     const nsecs_t refreshDuration = (timeDiff > 0) ? timeDiff : mMinRefreshDuration;
     mRefreshRateHistory.insertRefreshRate(refreshDuration);
 }
diff --git a/services/surfaceflinger/Scheduler/LayerInfo.h b/services/surfaceflinger/Scheduler/LayerInfo.h
index 02b6aef..2c50053 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.h
+++ b/services/surfaceflinger/Scheduler/LayerInfo.h
@@ -55,7 +55,7 @@
 
         float getRefreshRateAvg() const {
             nsecs_t refreshDuration = mMinRefreshDuration;
-            if (mElements.size() == HISTORY_SIZE) {
+            if (mElements.size() > 0) {
                 refreshDuration = scheduler::calculate_mean(mElements);
             }
 
@@ -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;
         }
 
@@ -101,10 +130,11 @@
     private:
         std::deque<nsecs_t> mElements;
         static constexpr size_t HISTORY_SIZE = 10;
+        static constexpr std::chrono::nanoseconds HISTORY_TIME = 500ms;
     };
 
 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..99d6fae 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -119,17 +119,19 @@
 }
 
 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 +140,28 @@
 }
 
 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 +286,13 @@
     }
 }
 
-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 +315,7 @@
     mPrimaryDispSync->setIgnorePresentFences(ignore);
 }
 
-nsecs_t Scheduler::expectedPresentTime() {
+nsecs_t Scheduler::getDispSyncExpectedPresentTime() {
     return mPrimaryDispSync->expectedPresentTime();
 }
 
@@ -324,8 +330,11 @@
             : 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(
@@ -404,6 +413,10 @@
     if (mSupportKernelTimer) {
         resetIdleTimer();
     }
+
+    // Touch event will boost the refresh rate to performance.
+    // Clear Layer History to get fresh FPS detection
+    mLayerHistory.clearHistory();
 }
 
 void Scheduler::resetTimerCallback() {
@@ -415,7 +428,7 @@
     ATRACE_INT("ExpiredKernelIdleTimer", 0);
     std::lock_guard<std::mutex> lock(mCallbackLock);
     if (mGetVsyncPeriod) {
-        resyncToHardwareVsync(false, mGetVsyncPeriod());
+        resyncToHardwareVsync(true, mGetVsyncPeriod());
     }
 }
 
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 96d4bd5..eaad37c 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -96,12 +96,13 @@
     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 +136,21 @@
 
     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);
@@ -179,7 +185,8 @@
 
 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:
@@ -192,7 +199,8 @@
     enum class TouchState { INACTIVE, ACTIVE };
 
     // 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);
@@ -292,7 +300,7 @@
     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..d452c19
--- /dev/null
+++ b/services/surfaceflinger/Scheduler/VSyncModulator.cpp
@@ -0,0 +1,177 @@
+/*
+ * 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();
+    const Offsets current = mOffsets;
+
+    bool changed = false;
+    if (desired.sf != current.sf) {
+        if (mSfConnectionHandle != nullptr) {
+            mScheduler->setPhaseOffset(mSfConnectionHandle, desired.sf);
+        } else if (mSfEventThread != nullptr) {
+            mSfEventThread->setPhaseOffset(desired.sf);
+        }
+        changed = true;
+    }
+    if (desired.app != current.app) {
+        if (mAppConnectionHandle != nullptr) {
+            mScheduler->setPhaseOffset(mAppConnectionHandle, desired.app);
+        } else if (mAppEventThread != nullptr) {
+            mAppEventThread->setPhaseOffset(desired.app);
+        }
+        changed = true;
+    }
+
+    if (changed) {
+        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..10cf8e6 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 +65,16 @@
     // 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; }
-
+    // Sets handles to the SF and app event threads.
     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) {
@@ -84,105 +83,43 @@
         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;
+    mutable std::mutex mMutex;
+    std::unordered_map<OffsetType, Offsets> mOffsetMap GUARDED_BY(mMutex);
+    nsecs_t mThresholdForNextVsync;
 
     EventThread* mSfEventThread = nullptr;
     EventThread* mAppEventThread = nullptr;
@@ -191,13 +128,15 @@
     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 2d31910..459cd0a 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -377,7 +377,8 @@
     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
@@ -616,13 +617,16 @@
             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(),
@@ -935,10 +939,13 @@
         // 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);
@@ -970,10 +977,10 @@
 
     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) {
@@ -982,6 +989,19 @@
     }
 }
 
+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) {
@@ -1011,10 +1031,7 @@
     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;
     }
 
@@ -1022,11 +1039,7 @@
     // 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;
@@ -1366,7 +1379,7 @@
 // ----------------------------------------------------------------------------
 
 sp<IDisplayEventConnection> SurfaceFlinger::createDisplayEventConnection(
-        ISurfaceComposer::VsyncSource vsyncSource) {
+        ISurfaceComposer::VsyncSource vsyncSource, ISurfaceComposer::ConfigChanged configChanged) {
     auto resyncCallback = mScheduler->makeResyncCallback([this] {
         Mutex::Autolock lock(mStateLock);
         return getVsyncPeriod();
@@ -1375,7 +1388,8 @@
     const auto& handle =
             vsyncSource == eVsyncSourceSurfaceFlinger ? mSfConnectionHandle : mAppConnectionHandle;
 
-    return mScheduler->createDisplayEventConnection(handle, std::move(resyncCallback));
+    return mScheduler->createDisplayEventConnection(handle, std::move(resyncCallback),
+                                                    configChanged);
 }
 
 // ----------------------------------------------------------------------------
@@ -1448,10 +1462,10 @@
         return;
     }
 
-    bool periodChanged = false;
-    mScheduler->addResyncSample(timestamp, &periodChanged);
-    if (periodChanged) {
-        mVsyncModulator.onRefreshRateChangeDetected();
+    bool periodFlushed = false;
+    mScheduler->addResyncSample(timestamp, &periodFlushed);
+    if (periodFlushed) {
+        mVsyncModulator.onRefreshRateChangeCompleted();
     }
 }
 
@@ -1524,10 +1538,23 @@
 
 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);
+        }
     }
 }
 
@@ -1637,6 +1664,18 @@
     return fence != Fence::NO_FENCE && (fence->getStatus() == Fence::Status::Unsignaled);
 }
 
+nsecs_t SurfaceFlinger::getExpectedPresentTime() 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.
+    const nsecs_t correctedTime =
+            mVsyncModulator.getOffsets().sf < mPhaseOffsets->getOffsetThresholdForNextVsync()
+            ? presentTime
+            : presentTime + stats.vsyncPeriod;
+    return correctedTime;
+}
+
 void SurfaceFlinger::onMessageReceived(int32_t what) NO_THREAD_SAFETY_ANALYSIS {
     ATRACE_CALL();
     switch (what) {
@@ -3245,8 +3284,7 @@
     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 {
@@ -3643,7 +3681,7 @@
 
 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 &&
@@ -4123,6 +4161,9 @@
     sp<GraphicBuffer> buffer;
     if (bufferChanged && cacheIdChanged) {
         ClientCache::getInstance().add(s.cachedBuffer, s.buffer);
+        ClientCache::getInstance().registerErasedRecipient(s.cachedBuffer,
+                                                           wp<ClientCache::ErasedRecipient>(layer));
+        getRenderEngine().cacheExternalTextureBuffer(s.buffer);
         buffer = s.buffer;
     } else if (cacheIdChanged) {
         buffer = ClientCache::getInstance().get(s.cachedBuffer);
@@ -4406,6 +4447,13 @@
             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__);
@@ -4432,6 +4480,7 @@
         // 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());
         }
@@ -4457,6 +4506,9 @@
             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
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index ddfe88c..6d4b2d7 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -293,11 +293,19 @@
     // 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);
 
+    // Returns 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.
+    nsecs_t getExpectedPresentTime();
+
     // for debugging only
     // TODO: this should be made accessible only to HWComposer
     const Vector<sp<Layer>>& getLayerSortedByZForHwcDisplay(DisplayId displayId);
@@ -399,7 +407,9 @@
             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 +518,15 @@
     // 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 +845,7 @@
     }
 
     bool previousFrameMissed();
+    void setVsyncEnabledInHWC(DisplayId displayId, HWC2::Vsync enabled);
 
     /*
      * Debugging & dumpsys
@@ -1166,6 +1179,10 @@
     // 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;
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/test.png b/services/surfaceflinger/test.png
new file mode 100644
index 0000000..773dcc3
--- /dev/null
+++ b/services/surfaceflinger/test.png
Binary files differ
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..7ec9066 100644
--- a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
+++ b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
@@ -25,6 +25,7 @@
 protected:
     std::unique_ptr<LayerHistory> mLayerHistory;
 
+    static constexpr float MIN_REFRESH_RATE = 30.f;
     static constexpr float MAX_REFRESH_RATE = 90.f;
 };
 
@@ -36,7 +37,7 @@
 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);
 
     mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
@@ -60,7 +61,7 @@
 
 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*/);
@@ -74,7 +75,7 @@
 
 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();
@@ -87,13 +88,13 @@
 
 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();
@@ -119,8 +120,8 @@
         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));
+    // After 1200 ms frames become obsolete.
+    std::this_thread::sleep_for(std::chrono::milliseconds(1500));
     // Insert the 31st frame.
     mLayerHistory->insert(test30FpsLayer, startTime + (30 * 33333333), 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));