SF: Isolate modesetting in DisplayModeController

Move the per-display state machine for modesetting from DisplayDevice to
DMC. In lieu of mStateLock, protect display lookup from multiple threads
using a mutex internal to DMC, which fixes the following deadlock:

OneShotTimer::loop
    SF::requestDisplayModes
    mStateLock

SF::commit
    mStateLock
    SF::processDisplayChangesLocked (hotplug or resolution change)
    Scheduler::demotePacesetterDisplay
    OneShotTimer::stop

A notable change is that {initiate,finalize}DisplayModeChange(s) are no
longer called under mStateLock, thanks to DMC's granular, internal lock.
finalizeDisplayModeChange still locks mStateLock for resolution changes.

Add an ActiveModeListener to DMC and register a callback in SF to update
the refresh rate overlay, which still lives in DisplayDevice for now.

Fixes: 329450361
Bug: 241285876
Test: DisplayModeControllerTest
Test: libsurfaceflinger_unittest
Change-Id: I30ec756f134d2d67a70ac8797008dc792eac035e
diff --git a/services/surfaceflinger/Display/DisplayModeController.cpp b/services/surfaceflinger/Display/DisplayModeController.cpp
index f093384..a6a9bec 100644
--- a/services/surfaceflinger/Display/DisplayModeController.cpp
+++ b/services/surfaceflinger/Display/DisplayModeController.cpp
@@ -20,30 +20,221 @@
 
 #include "Display/DisplayModeController.h"
 #include "Display/DisplaySnapshot.h"
+#include "DisplayHardware/HWComposer.h"
 
+#include <common/FlagManager.h>
+#include <ftl/concat.h>
+#include <ftl/expected.h>
 #include <log/log.h>
 
 namespace android::display {
 
+template <size_t N>
+inline std::string DisplayModeController::Display::concatId(const char (&str)[N]) const {
+    return std::string(ftl::Concat(str, ' ', snapshot.get().displayId().value).str());
+}
+
+DisplayModeController::Display::Display(DisplaySnapshotRef snapshot,
+                                        RefreshRateSelectorPtr selectorPtr)
+      : snapshot(snapshot),
+        selectorPtr(std::move(selectorPtr)),
+        pendingModeFpsTrace(concatId("PendingModeFps")),
+        activeModeFpsTrace(concatId("ActiveModeFps")),
+        renderRateFpsTrace(concatId("RenderRateFps")),
+        hasDesiredModeTrace(concatId("HasDesiredMode"), false) {}
+
+void DisplayModeController::registerDisplay(PhysicalDisplayId displayId,
+                                            DisplaySnapshotRef snapshotRef,
+                                            RefreshRateSelectorPtr selectorPtr) {
+    std::lock_guard lock(mDisplayLock);
+    mDisplays.emplace_or_replace(displayId, std::make_unique<Display>(snapshotRef, selectorPtr));
+}
+
 void DisplayModeController::registerDisplay(DisplaySnapshotRef snapshotRef,
                                             DisplayModeId activeModeId,
                                             scheduler::RefreshRateSelector::Config config) {
     const auto& snapshot = snapshotRef.get();
     const auto displayId = snapshot.displayId();
 
-    mDisplays.emplace_or_replace(displayId, snapshotRef, snapshot.displayModes(), activeModeId,
-                                 config);
+    std::lock_guard lock(mDisplayLock);
+    mDisplays.emplace_or_replace(displayId,
+                                 std::make_unique<Display>(snapshotRef, snapshot.displayModes(),
+                                                           activeModeId, config));
 }
 
 void DisplayModeController::unregisterDisplay(PhysicalDisplayId displayId) {
+    std::lock_guard lock(mDisplayLock);
     const bool ok = mDisplays.erase(displayId);
     ALOGE_IF(!ok, "%s: Unknown display %s", __func__, to_string(displayId).c_str());
 }
 
-auto DisplayModeController::selectorPtrFor(PhysicalDisplayId displayId) -> RefreshRateSelectorPtr {
+auto DisplayModeController::selectorPtrFor(PhysicalDisplayId displayId) const
+        -> RefreshRateSelectorPtr {
+    std::lock_guard lock(mDisplayLock);
     return mDisplays.get(displayId)
-            .transform([](const Display& display) { return display.selectorPtr; })
+            .transform([](const DisplayPtr& displayPtr) { return displayPtr->selectorPtr; })
             .value_or(nullptr);
 }
 
+auto DisplayModeController::setDesiredMode(PhysicalDisplayId displayId,
+                                           DisplayModeRequest&& desiredMode) -> DesiredModeAction {
+    std::lock_guard lock(mDisplayLock);
+    const auto& displayPtr =
+            FTL_EXPECT(mDisplays.get(displayId).ok_or(DesiredModeAction::None)).get();
+
+    {
+        ATRACE_NAME(displayPtr->concatId(__func__).c_str());
+        ALOGD("%s %s", displayPtr->concatId(__func__).c_str(), to_string(desiredMode).c_str());
+
+        std::scoped_lock lock(displayPtr->desiredModeLock);
+
+        if (auto& desiredModeOpt = displayPtr->desiredModeOpt) {
+            // A mode transition was already scheduled, so just override the desired mode.
+            const bool emitEvent = desiredModeOpt->emitEvent;
+            const bool force = desiredModeOpt->force;
+            desiredModeOpt = std::move(desiredMode);
+            desiredModeOpt->emitEvent |= emitEvent;
+            if (FlagManager::getInstance().connected_display()) {
+                desiredModeOpt->force |= force;
+            }
+            return DesiredModeAction::None;
+        }
+
+        // If the desired mode is already active...
+        const auto activeMode = displayPtr->selectorPtr->getActiveMode();
+        if (const auto& desiredModePtr = desiredMode.mode.modePtr;
+            !desiredMode.force && activeMode.modePtr->getId() == desiredModePtr->getId()) {
+            if (activeMode == desiredMode.mode) {
+                return DesiredModeAction::None;
+            }
+
+            // ...but the render rate changed:
+            setActiveModeLocked(displayId, desiredModePtr->getId(), desiredModePtr->getVsyncRate(),
+                                desiredMode.mode.fps);
+            return DesiredModeAction::InitiateRenderRateSwitch;
+        }
+
+        // Restore peak render rate to schedule the next frame as soon as possible.
+        setActiveModeLocked(displayId, activeMode.modePtr->getId(),
+                            activeMode.modePtr->getVsyncRate(), activeMode.modePtr->getPeakFps());
+
+        // Initiate a mode change.
+        displayPtr->desiredModeOpt = std::move(desiredMode);
+        displayPtr->hasDesiredModeTrace = true;
+    }
+
+    return DesiredModeAction::InitiateDisplayModeSwitch;
+}
+
+auto DisplayModeController::getDesiredMode(PhysicalDisplayId displayId) const
+        -> DisplayModeRequestOpt {
+    std::lock_guard lock(mDisplayLock);
+    const auto& displayPtr =
+            FTL_EXPECT(mDisplays.get(displayId).ok_or(DisplayModeRequestOpt())).get();
+
+    {
+        std::scoped_lock lock(displayPtr->desiredModeLock);
+        return displayPtr->desiredModeOpt;
+    }
+}
+
+auto DisplayModeController::getPendingMode(PhysicalDisplayId displayId) const
+        -> DisplayModeRequestOpt {
+    std::lock_guard lock(mDisplayLock);
+    const auto& displayPtr =
+            FTL_EXPECT(mDisplays.get(displayId).ok_or(DisplayModeRequestOpt())).get();
+
+    {
+        std::scoped_lock lock(displayPtr->desiredModeLock);
+        return displayPtr->pendingModeOpt;
+    }
+}
+
+bool DisplayModeController::isModeSetPending(PhysicalDisplayId displayId) const {
+    std::lock_guard lock(mDisplayLock);
+    const auto& displayPtr = FTL_EXPECT(mDisplays.get(displayId).ok_or(false)).get();
+
+    {
+        std::scoped_lock lock(displayPtr->desiredModeLock);
+        return displayPtr->isModeSetPending;
+    }
+}
+
+scheduler::FrameRateMode DisplayModeController::getActiveMode(PhysicalDisplayId displayId) const {
+    return selectorPtrFor(displayId)->getActiveMode();
+}
+
+void DisplayModeController::clearDesiredMode(PhysicalDisplayId displayId) {
+    std::lock_guard lock(mDisplayLock);
+    const auto& displayPtr = FTL_TRY(mDisplays.get(displayId).ok_or(ftl::Unit())).get();
+
+    {
+        std::scoped_lock lock(displayPtr->desiredModeLock);
+        displayPtr->desiredModeOpt.reset();
+        displayPtr->hasDesiredModeTrace = false;
+    }
+}
+
+bool DisplayModeController::initiateModeChange(PhysicalDisplayId displayId,
+                                               DisplayModeRequest&& desiredMode,
+                                               const hal::VsyncPeriodChangeConstraints& constraints,
+                                               hal::VsyncPeriodChangeTimeline& outTimeline) {
+    std::lock_guard lock(mDisplayLock);
+    const auto& displayPtr = FTL_EXPECT(mDisplays.get(displayId).ok_or(false)).get();
+
+    // TODO: b/255635711 - Flow the DisplayModeRequest through the desired/pending/active states.
+    // For now, `desiredMode` and `desiredModeOpt` are one and the same, but the latter is not
+    // cleared until the next `SF::initiateDisplayModeChanges`. However, the desired mode has been
+    // consumed at this point, so clear the `force` flag to prevent an endless loop of
+    // `initiateModeChange`.
+    if (FlagManager::getInstance().connected_display()) {
+        std::scoped_lock lock(displayPtr->desiredModeLock);
+        if (displayPtr->desiredModeOpt) {
+            displayPtr->desiredModeOpt->force = false;
+        }
+    }
+
+    displayPtr->pendingModeOpt = std::move(desiredMode);
+    displayPtr->isModeSetPending = true;
+
+    const auto& mode = *displayPtr->pendingModeOpt->mode.modePtr;
+
+    if (mComposerPtr->setActiveModeWithConstraints(displayId, mode.getHwcId(), constraints,
+                                                   &outTimeline) != OK) {
+        return false;
+    }
+
+    ATRACE_INT(displayPtr->pendingModeFpsTrace.c_str(), mode.getVsyncRate().getIntValue());
+    return true;
+}
+
+void DisplayModeController::finalizeModeChange(PhysicalDisplayId displayId, DisplayModeId modeId,
+                                               Fps vsyncRate, Fps renderFps) {
+    std::lock_guard lock(mDisplayLock);
+    setActiveModeLocked(displayId, modeId, vsyncRate, renderFps);
+
+    const auto& displayPtr = FTL_TRY(mDisplays.get(displayId).ok_or(ftl::Unit())).get();
+    displayPtr->isModeSetPending = false;
+}
+
+void DisplayModeController::setActiveMode(PhysicalDisplayId displayId, DisplayModeId modeId,
+                                          Fps vsyncRate, Fps renderFps) {
+    std::lock_guard lock(mDisplayLock);
+    setActiveModeLocked(displayId, modeId, vsyncRate, renderFps);
+}
+
+void DisplayModeController::setActiveModeLocked(PhysicalDisplayId displayId, DisplayModeId modeId,
+                                                Fps vsyncRate, Fps renderFps) {
+    const auto& displayPtr = FTL_TRY(mDisplays.get(displayId).ok_or(ftl::Unit())).get();
+
+    ATRACE_INT(displayPtr->activeModeFpsTrace.c_str(), vsyncRate.getIntValue());
+    ATRACE_INT(displayPtr->renderRateFpsTrace.c_str(), renderFps.getIntValue());
+
+    displayPtr->selectorPtr->setActiveMode(modeId, renderFps);
+
+    if (mActiveModeListener) {
+        mActiveModeListener(displayId, vsyncRate, renderFps);
+    }
+}
+
 } // namespace android::display
diff --git a/services/surfaceflinger/Display/DisplayModeController.h b/services/surfaceflinger/Display/DisplayModeController.h
index b6a6bee..258b04b 100644
--- a/services/surfaceflinger/Display/DisplayModeController.h
+++ b/services/surfaceflinger/Display/DisplayModeController.h
@@ -17,16 +17,26 @@
 #pragma once
 
 #include <memory>
+#include <mutex>
+#include <string>
 #include <utility>
 
 #include <android-base/thread_annotations.h>
+#include <ftl/function.h>
+#include <ftl/optional.h>
 #include <ui/DisplayId.h>
 #include <ui/DisplayMap.h>
 
+#include "Display/DisplayModeRequest.h"
 #include "Display/DisplaySnapshotRef.h"
 #include "DisplayHardware/DisplayMode.h"
 #include "Scheduler/RefreshRateSelector.h"
 #include "ThreadContext.h"
+#include "TracedOrdinal.h"
+
+namespace android {
+class HWComposer;
+} // namespace android
 
 namespace android::display {
 
@@ -34,40 +44,97 @@
 // certain heuristic signals.
 class DisplayModeController {
 public:
-    // The referenced DisplaySnapshot must outlive the registration.
-    void registerDisplay(DisplaySnapshotRef, DisplayModeId, scheduler::RefreshRateSelector::Config)
-            REQUIRES(kMainThreadContext);
-    void unregisterDisplay(PhysicalDisplayId) REQUIRES(kMainThreadContext);
+    using ActiveModeListener = ftl::Function<void(PhysicalDisplayId, Fps vsyncRate, Fps renderFps)>;
 
-    // TODO(b/241285876): Remove once ownership is no longer shared with DisplayDevice.
+    DisplayModeController() = default;
+
+    void setHwComposer(HWComposer* composerPtr) { mComposerPtr = composerPtr; }
+    void setActiveModeListener(const ActiveModeListener& listener) {
+        mActiveModeListener = listener;
+    }
+
+    // TODO: b/241285876 - Remove once ownership is no longer shared with DisplayDevice.
     using RefreshRateSelectorPtr = std::shared_ptr<scheduler::RefreshRateSelector>;
 
-    // Returns `nullptr` if the display is no longer registered (or never was).
-    RefreshRateSelectorPtr selectorPtrFor(PhysicalDisplayId) REQUIRES(kMainThreadContext);
-
     // Used by tests to inject an existing RefreshRateSelector.
-    // TODO(b/241285876): Remove this.
-    void registerDisplay(PhysicalDisplayId displayId, DisplaySnapshotRef snapshotRef,
-                         RefreshRateSelectorPtr selectorPtr) {
-        mDisplays.emplace_or_replace(displayId, snapshotRef, selectorPtr);
-    }
+    // TODO: b/241285876 - Remove this.
+    void registerDisplay(PhysicalDisplayId, DisplaySnapshotRef, RefreshRateSelectorPtr)
+            EXCLUDES(mDisplayLock);
+
+    // The referenced DisplaySnapshot must outlive the registration.
+    void registerDisplay(DisplaySnapshotRef, DisplayModeId, scheduler::RefreshRateSelector::Config)
+            REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
+    void unregisterDisplay(PhysicalDisplayId) REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
+
+    // Returns `nullptr` if the display is no longer registered (or never was).
+    RefreshRateSelectorPtr selectorPtrFor(PhysicalDisplayId) const EXCLUDES(mDisplayLock);
+
+    enum class DesiredModeAction { None, InitiateDisplayModeSwitch, InitiateRenderRateSwitch };
+
+    DesiredModeAction setDesiredMode(PhysicalDisplayId, DisplayModeRequest&&)
+            EXCLUDES(mDisplayLock);
+
+    using DisplayModeRequestOpt = ftl::Optional<DisplayModeRequest>;
+
+    DisplayModeRequestOpt getDesiredMode(PhysicalDisplayId) const EXCLUDES(mDisplayLock);
+    void clearDesiredMode(PhysicalDisplayId) EXCLUDES(mDisplayLock);
+
+    DisplayModeRequestOpt getPendingMode(PhysicalDisplayId) const REQUIRES(kMainThreadContext)
+            EXCLUDES(mDisplayLock);
+    bool isModeSetPending(PhysicalDisplayId) const REQUIRES(kMainThreadContext)
+            EXCLUDES(mDisplayLock);
+
+    scheduler::FrameRateMode getActiveMode(PhysicalDisplayId) const EXCLUDES(mDisplayLock);
+
+    bool initiateModeChange(PhysicalDisplayId, DisplayModeRequest&&,
+                            const hal::VsyncPeriodChangeConstraints&,
+                            hal::VsyncPeriodChangeTimeline& outTimeline)
+            REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
+
+    void finalizeModeChange(PhysicalDisplayId, DisplayModeId, Fps vsyncRate, Fps renderFps)
+            REQUIRES(kMainThreadContext) EXCLUDES(mDisplayLock);
+
+    void setActiveMode(PhysicalDisplayId, DisplayModeId, Fps vsyncRate, Fps renderFps)
+            EXCLUDES(mDisplayLock);
 
 private:
     struct Display {
-        Display(DisplaySnapshotRef snapshot, RefreshRateSelectorPtr selectorPtr)
-              : snapshot(snapshot), selectorPtr(std::move(selectorPtr)) {}
+        template <size_t N>
+        std::string concatId(const char (&)[N]) const;
 
+        Display(DisplaySnapshotRef, RefreshRateSelectorPtr);
         Display(DisplaySnapshotRef snapshot, DisplayModes modes, DisplayModeId activeModeId,
                 scheduler::RefreshRateSelector::Config config)
               : Display(snapshot,
                         std::make_shared<scheduler::RefreshRateSelector>(std::move(modes),
                                                                          activeModeId, config)) {}
-
         const DisplaySnapshotRef snapshot;
         const RefreshRateSelectorPtr selectorPtr;
+
+        const std::string pendingModeFpsTrace;
+        const std::string activeModeFpsTrace;
+        const std::string renderRateFpsTrace;
+
+        std::mutex desiredModeLock;
+        DisplayModeRequestOpt desiredModeOpt GUARDED_BY(desiredModeLock);
+        TracedOrdinal<bool> hasDesiredModeTrace GUARDED_BY(desiredModeLock);
+
+        DisplayModeRequestOpt pendingModeOpt GUARDED_BY(kMainThreadContext);
+        bool isModeSetPending GUARDED_BY(kMainThreadContext) = false;
     };
 
-    ui::PhysicalDisplayMap<PhysicalDisplayId, Display> mDisplays;
+    using DisplayPtr = std::unique_ptr<Display>;
+
+    void setActiveModeLocked(PhysicalDisplayId, DisplayModeId, Fps vsyncRate, Fps renderFps)
+            REQUIRES(mDisplayLock);
+
+    // Set once when initializing the DisplayModeController, which the HWComposer must outlive.
+    HWComposer* mComposerPtr = nullptr;
+
+    ActiveModeListener mActiveModeListener;
+
+    mutable std::mutex mDisplayLock;
+    ui::PhysicalDisplayMap<PhysicalDisplayId, DisplayPtr> mDisplays GUARDED_BY(mDisplayLock);
 };
 
 } // namespace android::display
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index a57e626..27ea4a9 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -24,7 +24,6 @@
 
 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
 
-#include <common/FlagManager.h>
 #include <compositionengine/CompositionEngine.h>
 #include <compositionengine/Display.h>
 #include <compositionengine/DisplayColorProfile.h>
@@ -36,6 +35,7 @@
 #include <compositionengine/RenderSurfaceCreationArgs.h>
 #include <compositionengine/impl/OutputCompositionState.h>
 #include <configstore/Utils.h>
+#include <ftl/concat.h>
 #include <log/log.h>
 #include <system/window.h>
 
@@ -64,15 +64,11 @@
         mDisplayToken(args.displayToken),
         mSequenceId(args.sequenceId),
         mCompositionDisplay{args.compositionDisplay},
-        mPendingModeFpsTrace(concatId("PendingModeFps")),
-        mActiveModeFpsTrace(concatId("ActiveModeFps")),
-        mRenderRateFpsTrace(concatId("RenderRateFps")),
         mPhysicalOrientation(args.physicalOrientation),
         mPowerMode(ftl::Concat("PowerMode ", getId().value).c_str(), args.initialPowerMode),
         mIsPrimary(args.isPrimary),
         mRequestedRefreshRate(args.requestedRefreshRate),
-        mRefreshRateSelector(std::move(args.refreshRateSelector)),
-        mHasDesiredModeTrace(concatId("HasDesiredMode"), false) {
+        mRefreshRateSelector(std::move(args.refreshRateSelector)) {
     mCompositionDisplay->editState().isSecure = args.isSecure;
     mCompositionDisplay->editState().isProtected = args.isProtected;
     mCompositionDisplay->createRenderSurface(
@@ -204,47 +200,6 @@
     return mPowerMode != hal::PowerMode::OFF;
 }
 
-void DisplayDevice::setActiveMode(DisplayModeId modeId, Fps vsyncRate, Fps renderFps) {
-    ATRACE_INT(mActiveModeFpsTrace.c_str(), vsyncRate.getIntValue());
-    ATRACE_INT(mRenderRateFpsTrace.c_str(), renderFps.getIntValue());
-
-    mRefreshRateSelector->setActiveMode(modeId, renderFps);
-    updateRefreshRateOverlayRate(vsyncRate, renderFps);
-}
-
-bool DisplayDevice::initiateModeChange(display::DisplayModeRequest&& desiredMode,
-                                       const hal::VsyncPeriodChangeConstraints& constraints,
-                                       hal::VsyncPeriodChangeTimeline& outTimeline) {
-    // TODO(b/255635711): Flow the DisplayModeRequest through the desired/pending/active states. For
-    // now, `desiredMode` and `mDesiredModeOpt` are one and the same, but the latter is not cleared
-    // until the next `SF::initiateDisplayModeChanges`. However, the desired mode has been consumed
-    // at this point, so clear the `force` flag to prevent an endless loop of `initiateModeChange`.
-    if (FlagManager::getInstance().connected_display()) {
-        std::scoped_lock lock(mDesiredModeLock);
-        if (mDesiredModeOpt) {
-            mDesiredModeOpt->force = false;
-        }
-    }
-
-    mPendingModeOpt = std::move(desiredMode);
-    mIsModeSetPending = true;
-
-    const auto& mode = *mPendingModeOpt->mode.modePtr;
-
-    if (mHwComposer.setActiveModeWithConstraints(getPhysicalId(), mode.getHwcId(), constraints,
-                                                 &outTimeline) != OK) {
-        return false;
-    }
-
-    ATRACE_INT(mPendingModeFpsTrace.c_str(), mode.getVsyncRate().getIntValue());
-    return true;
-}
-
-void DisplayDevice::finalizeModeChange(DisplayModeId modeId, Fps vsyncRate, Fps renderFps) {
-    setActiveMode(modeId, vsyncRate, renderFps);
-    mIsModeSetPending = false;
-}
-
 nsecs_t DisplayDevice::getVsyncPeriodFromHWC() const {
     const auto physicalId = getPhysicalId();
     if (!mHwComposer.isConnected(physicalId)) {
@@ -450,8 +405,9 @@
     }
 }
 
-void DisplayDevice::enableRefreshRateOverlay(bool enable, bool setByHwc, bool showSpinner,
-                                             bool showRenderRate, bool showInMiddle) {
+void DisplayDevice::enableRefreshRateOverlay(bool enable, bool setByHwc, Fps refreshRate,
+                                             Fps renderFps, bool showSpinner, bool showRenderRate,
+                                             bool showInMiddle) {
     if (!enable) {
         mRefreshRateOverlay.reset();
         return;
@@ -479,8 +435,7 @@
     if (mRefreshRateOverlay) {
         mRefreshRateOverlay->setLayerStack(getLayerStack());
         mRefreshRateOverlay->setViewport(getSize());
-        updateRefreshRateOverlayRate(getActiveMode().modePtr->getVsyncRate(), getActiveMode().fps,
-                                     setByHwc);
+        updateRefreshRateOverlayRate(refreshRate, renderFps, setByHwc);
     }
 }
 
@@ -531,57 +486,6 @@
     }
 }
 
-auto DisplayDevice::setDesiredMode(display::DisplayModeRequest&& desiredMode) -> DesiredModeAction {
-    ATRACE_NAME(concatId(__func__).c_str());
-    ALOGD("%s %s", concatId(__func__).c_str(), to_string(desiredMode).c_str());
-
-    std::scoped_lock lock(mDesiredModeLock);
-    if (mDesiredModeOpt) {
-        // A mode transition was already scheduled, so just override the desired mode.
-        const bool emitEvent = mDesiredModeOpt->emitEvent;
-        const bool force = mDesiredModeOpt->force;
-        mDesiredModeOpt = std::move(desiredMode);
-        mDesiredModeOpt->emitEvent |= emitEvent;
-        if (FlagManager::getInstance().connected_display()) {
-            mDesiredModeOpt->force |= force;
-        }
-        return DesiredModeAction::None;
-    }
-
-    // If the desired mode is already active...
-    const auto activeMode = refreshRateSelector().getActiveMode();
-    if (const auto& desiredModePtr = desiredMode.mode.modePtr;
-        !desiredMode.force && activeMode.modePtr->getId() == desiredModePtr->getId()) {
-        if (activeMode == desiredMode.mode) {
-            return DesiredModeAction::None;
-        }
-
-        // ...but the render rate changed:
-        setActiveMode(desiredModePtr->getId(), desiredModePtr->getVsyncRate(),
-                      desiredMode.mode.fps);
-        return DesiredModeAction::InitiateRenderRateSwitch;
-    }
-
-    setActiveMode(activeMode.modePtr->getId(), activeMode.modePtr->getVsyncRate(),
-                  activeMode.modePtr->getPeakFps());
-
-    // Initiate a mode change.
-    mDesiredModeOpt = std::move(desiredMode);
-    mHasDesiredModeTrace = true;
-    return DesiredModeAction::InitiateDisplayModeSwitch;
-}
-
-auto DisplayDevice::getDesiredMode() const -> DisplayModeRequestOpt {
-    std::scoped_lock lock(mDesiredModeLock);
-    return mDesiredModeOpt;
-}
-
-void DisplayDevice::clearDesiredMode() {
-    std::scoped_lock lock(mDesiredModeLock);
-    mDesiredModeOpt.reset();
-    mHasDesiredModeTrace = false;
-}
-
 void DisplayDevice::adjustRefreshRate(Fps pacesetterDisplayRefreshRate) {
     using fps_approx_ops::operator<=;
     if (mRequestedRefreshRate <= 0_Hz) {
diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index a21559f..3cc8cf5 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -23,8 +23,6 @@
 #include <android-base/thread_annotations.h>
 #include <android/native_window.h>
 #include <binder/IBinder.h>
-#include <ftl/concat.h>
-#include <ftl/optional.h>
 #include <gui/LayerState.h>
 #include <math/mat4.h>
 #include <renderengine/RenderEngine.h>
@@ -42,7 +40,6 @@
 #include <utils/RefBase.h>
 #include <utils/Timers.h>
 
-#include "Display/DisplayModeRequest.h"
 #include "DisplayHardware/DisplayMode.h"
 #include "DisplayHardware/Hal.h"
 #include "DisplayHardware/PowerAdvisor.h"
@@ -183,37 +180,6 @@
 
     ui::Dataspace getCompositionDataSpace() const;
 
-    /* ------------------------------------------------------------------------
-     * Display mode management.
-     */
-
-    enum class DesiredModeAction { None, InitiateDisplayModeSwitch, InitiateRenderRateSwitch };
-
-    DesiredModeAction setDesiredMode(display::DisplayModeRequest&&) EXCLUDES(mDesiredModeLock);
-
-    using DisplayModeRequestOpt = ftl::Optional<display::DisplayModeRequest>;
-
-    DisplayModeRequestOpt getDesiredMode() const EXCLUDES(mDesiredModeLock);
-    void clearDesiredMode() EXCLUDES(mDesiredModeLock);
-
-    DisplayModeRequestOpt getPendingMode() const REQUIRES(kMainThreadContext) {
-        return mPendingModeOpt;
-    }
-    bool isModeSetPending() const REQUIRES(kMainThreadContext) { return mIsModeSetPending; }
-
-    scheduler::FrameRateMode getActiveMode() const REQUIRES(kMainThreadContext) {
-        return mRefreshRateSelector->getActiveMode();
-    }
-
-    void setActiveMode(DisplayModeId, Fps vsyncRate, Fps renderFps);
-
-    bool initiateModeChange(display::DisplayModeRequest&&, const hal::VsyncPeriodChangeConstraints&,
-                            hal::VsyncPeriodChangeTimeline& outTimeline)
-            REQUIRES(kMainThreadContext);
-
-    void finalizeModeChange(DisplayModeId, Fps vsyncRate, Fps renderFps)
-            REQUIRES(kMainThreadContext);
-
     scheduler::RefreshRateSelector& refreshRateSelector() const { return *mRefreshRateSelector; }
 
     // Extends the lifetime of the RefreshRateSelector, so it can outlive this DisplayDevice.
@@ -221,13 +187,14 @@
         return mRefreshRateSelector;
     }
 
-    void animateOverlay();
-
     // Enables an overlay to be displayed with the current refresh rate
-    void enableRefreshRateOverlay(bool enable, bool setByHwc, bool showSpinner, bool showRenderRate,
-                                  bool showInMiddle) REQUIRES(kMainThreadContext);
+    // TODO(b/241285876): Move overlay to DisplayModeController.
+    void enableRefreshRateOverlay(bool enable, bool setByHwc, Fps refreshRate, Fps renderFps,
+                                  bool showSpinner, bool showRenderRate, bool showInMiddle)
+            REQUIRES(kMainThreadContext);
     void updateRefreshRateOverlayRate(Fps refreshRate, Fps renderFps, bool setByHwc = false);
     bool isRefreshRateOverlayEnabled() const { return mRefreshRateOverlay != nullptr; }
+    void animateOverlay();
     bool onKernelTimerChanged(std::optional<DisplayModeId>, bool timerExpired);
 
     // Enables an overlay to be display with the hdr/sdr ratio
@@ -249,11 +216,6 @@
     void dump(utils::Dumper&) const;
 
 private:
-    template <size_t N>
-    inline std::string concatId(const char (&str)[N]) const {
-        return std::string(ftl::Concat(str, ' ', getId().value).str());
-    }
-
     const sp<SurfaceFlinger> mFlinger;
     HWComposer& mHwComposer;
     const wp<IBinder> mDisplayToken;
@@ -262,9 +224,6 @@
     const std::shared_ptr<compositionengine::Display> mCompositionDisplay;
 
     std::string mDisplayName;
-    std::string mPendingModeFpsTrace;
-    std::string mActiveModeFpsTrace;
-    std::string mRenderRateFpsTrace;
 
     const ui::Rotation mPhysicalOrientation;
     ui::Rotation mOrientation = ui::ROTATION_0;
@@ -296,13 +255,6 @@
     std::unique_ptr<HdrSdrRatioOverlay> mHdrSdrRatioOverlay;
     // This parameter is only used for hdr/sdr ratio overlay
     float mHdrSdrRatio = 1.0f;
-
-    mutable std::mutex mDesiredModeLock;
-    DisplayModeRequestOpt mDesiredModeOpt GUARDED_BY(mDesiredModeLock);
-    TracedOrdinal<bool> mHasDesiredModeTrace GUARDED_BY(mDesiredModeLock);
-
-    DisplayModeRequestOpt mPendingModeOpt GUARDED_BY(kMainThreadContext);
-    bool mIsModeSetPending GUARDED_BY(kMainThreadContext) = false;
 };
 
 struct DisplayDeviceState {
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 59345db..b1d7750 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -891,8 +891,12 @@
     }
 
     mCompositionEngine->setTimeStats(mTimeStats);
+
     mCompositionEngine->setHwComposer(getFactory().createHWComposer(mHwcServiceName));
-    mCompositionEngine->getHwComposer().setCallback(*this);
+    auto& composer = mCompositionEngine->getHwComposer();
+    composer.setCallback(*this);
+    mDisplayModeController.setHwComposer(&composer);
+
     ClientCache::getInstance().setRenderEngine(&getRenderEngine());
 
     mHasReliablePresentFences =
@@ -931,6 +935,20 @@
     // initializing the Scheduler after configureLocked, once decoupled from DisplayDevice.
     initScheduler(display);
 
+    // Start listening after creating the Scheduler, since the listener calls into it.
+    mDisplayModeController.setActiveModeListener(
+            display::DisplayModeController::ActiveModeListener::make(
+                    [this](PhysicalDisplayId displayId, Fps vsyncRate, Fps renderRate) {
+                        // This callback cannot lock mStateLock, as some callers already lock it.
+                        // Instead, switch context to the main thread.
+                        static_cast<void>(mScheduler->schedule([=,
+                                                                this]() FTL_FAKE_GUARD(mStateLock) {
+                            if (const auto display = getDisplayDeviceLocked(displayId)) {
+                                display->updateRefreshRateOverlayRate(vsyncRate, renderRate);
+                            }
+                        }));
+                    }));
+
     mLayerTracing.setTakeLayersSnapshotProtoFunction([&](uint32_t traceFlags) {
         auto snapshot = perfetto::protos::LayersSnapshotProto{};
         mScheduler
@@ -1296,19 +1314,19 @@
 
     ATRACE_NAME(ftl::Concat(__func__, ' ', displayId.value).c_str());
 
-    const auto display = getDisplayDeviceLocked(displayId);
-    if (!display) {
-        ALOGW("%s: display is no longer valid", __func__);
-        return;
-    }
-
     const bool emitEvent = desiredMode.emitEvent;
 
-    switch (display->setDesiredMode(std::move(desiredMode))) {
-        case DisplayDevice::DesiredModeAction::InitiateDisplayModeSwitch:
-            // DisplayDevice::setDesiredMode updated the render rate, so inform Scheduler.
-            mScheduler->setRenderRate(displayId, display->refreshRateSelector().getActiveMode().fps,
-                                      /*applyImmediately*/ true);
+    using DesiredModeAction = display::DisplayModeController::DesiredModeAction;
+
+    switch (mDisplayModeController.setDesiredMode(displayId, std::move(desiredMode))) {
+        case DesiredModeAction::InitiateDisplayModeSwitch: {
+            const auto selectorPtr = mDisplayModeController.selectorPtrFor(displayId);
+            if (!selectorPtr) break;
+
+            const Fps renderRate = selectorPtr->getActiveMode().fps;
+
+            // DisplayModeController::setDesiredMode updated the render rate, so inform Scheduler.
+            mScheduler->setRenderRate(displayId, renderRate, true /* applyImmediately */);
 
             // Schedule a new frame to initiate the display mode switch.
             scheduleComposite(FrameHint::kNone);
@@ -1328,7 +1346,8 @@
 
             mScheduler->setModeChangePending(true);
             break;
-        case DisplayDevice::DesiredModeAction::InitiateRenderRateSwitch:
+        }
+        case DesiredModeAction::InitiateRenderRateSwitch:
             mScheduler->setRenderRate(displayId, mode.fps, /*applyImmediately*/ false);
 
             if (displayId == mActiveDisplayId) {
@@ -1339,7 +1358,7 @@
                 dispatchDisplayModeChangeEvent(displayId, mode);
             }
             break;
-        case DisplayDevice::DesiredModeAction::None:
+        case DesiredModeAction::None:
             break;
     }
 }
@@ -1395,11 +1414,10 @@
     return future.get();
 }
 
-void SurfaceFlinger::finalizeDisplayModeChange(DisplayDevice& display) {
-    const auto displayId = display.getPhysicalId();
+void SurfaceFlinger::finalizeDisplayModeChange(PhysicalDisplayId displayId) {
     ATRACE_NAME(ftl::Concat(__func__, ' ', displayId.value).c_str());
 
-    const auto pendingModeOpt = display.getPendingMode();
+    const auto pendingModeOpt = mDisplayModeController.getPendingMode(displayId);
     if (!pendingModeOpt) {
         // There is no pending mode change. This can happen if the active
         // display changed and the mode change happened on a different display.
@@ -1408,8 +1426,12 @@
 
     const auto& activeMode = pendingModeOpt->mode;
 
-    if (display.getActiveMode().modePtr->getResolution() != activeMode.modePtr->getResolution()) {
-        auto& state = mCurrentState.displays.editValueFor(display.getDisplayToken());
+    if (const auto oldResolution =
+                mDisplayModeController.getActiveMode(displayId).modePtr->getResolution();
+        oldResolution != activeMode.modePtr->getResolution()) {
+        Mutex::Autolock lock(mStateLock);
+
+        auto& state = mCurrentState.displays.editValueFor(getPhysicalDisplayTokenLocked(displayId));
         // We need to generate new sequenceId in order to recreate the display (and this
         // way the framebuffer).
         state.sequenceId = DisplayDeviceState{}.sequenceId;
@@ -1420,8 +1442,8 @@
         return;
     }
 
-    display.finalizeModeChange(activeMode.modePtr->getId(), activeMode.modePtr->getVsyncRate(),
-                               activeMode.fps);
+    mDisplayModeController.finalizeModeChange(displayId, activeMode.modePtr->getId(),
+                                              activeMode.modePtr->getVsyncRate(), activeMode.fps);
 
     if (displayId == mActiveDisplayId) {
         mScheduler->updatePhaseConfiguration(activeMode.fps);
@@ -1432,21 +1454,20 @@
     }
 }
 
-void SurfaceFlinger::dropModeRequest(const sp<DisplayDevice>& display) {
-    display->clearDesiredMode();
-    if (display->getPhysicalId() == mActiveDisplayId) {
+void SurfaceFlinger::dropModeRequest(PhysicalDisplayId displayId) {
+    mDisplayModeController.clearDesiredMode(displayId);
+    if (displayId == mActiveDisplayId) {
         // TODO(b/255635711): Check for pending mode changes on other displays.
         mScheduler->setModeChangePending(false);
     }
 }
 
-void SurfaceFlinger::applyActiveMode(const sp<DisplayDevice>& display) {
-    const auto activeModeOpt = display->getDesiredMode();
+void SurfaceFlinger::applyActiveMode(PhysicalDisplayId displayId) {
+    const auto activeModeOpt = mDisplayModeController.getDesiredMode(displayId);
     auto activeModePtr = activeModeOpt->mode.modePtr;
-    const auto displayId = activeModePtr->getPhysicalDisplayId();
     const auto renderFps = activeModeOpt->mode.fps;
 
-    dropModeRequest(display);
+    dropModeRequest(displayId);
 
     constexpr bool kAllowToEnable = true;
     mScheduler->resyncToHardwareVsync(displayId, kAllowToEnable, std::move(activeModePtr).take());
@@ -1462,11 +1483,8 @@
 
     std::optional<PhysicalDisplayId> displayToUpdateImmediately;
 
-    for (const auto& [id, physical] : mPhysicalDisplays) {
-        const auto display = getDisplayDeviceLocked(id);
-        if (!display) continue;
-
-        auto desiredModeOpt = display->getDesiredMode();
+    for (const auto& [displayId, physical] : FTL_FAKE_GUARD(mStateLock, mPhysicalDisplays)) {
+        auto desiredModeOpt = mDisplayModeController.getDesiredMode(displayId);
         if (!desiredModeOpt) {
             continue;
         }
@@ -1483,19 +1501,21 @@
         ALOGV("%s changing active mode to %d(%s) for display %s", __func__,
               ftl::to_underlying(desiredModeId),
               to_string(displayModePtrOpt->get()->getVsyncRate()).c_str(),
-              to_string(display->getId()).c_str());
+              to_string(displayId).c_str());
 
         if ((!FlagManager::getInstance().connected_display() || !desiredModeOpt->force) &&
-            display->getActiveMode() == desiredModeOpt->mode) {
-            applyActiveMode(display);
+            mDisplayModeController.getActiveMode(displayId) == desiredModeOpt->mode) {
+            applyActiveMode(displayId);
             continue;
         }
 
+        const auto selectorPtr = mDisplayModeController.selectorPtrFor(displayId);
+
         // Desired active mode was set, it is different than the mode currently in use, however
         // allowed modes might have changed by the time we process the refresh.
         // Make sure the desired mode is still allowed
-        if (!display->refreshRateSelector().isModeAllowed(desiredModeOpt->mode)) {
-            dropModeRequest(display);
+        if (!selectorPtr->isModeAllowed(desiredModeOpt->mode)) {
+            dropModeRequest(displayId);
             continue;
         }
 
@@ -1505,11 +1525,12 @@
         constraints.seamlessRequired = false;
         hal::VsyncPeriodChangeTimeline outTimeline;
 
-        if (!display->initiateModeChange(std::move(*desiredModeOpt), constraints, outTimeline)) {
+        if (!mDisplayModeController.initiateModeChange(displayId, std::move(*desiredModeOpt),
+                                                       constraints, outTimeline)) {
             continue;
         }
 
-        display->refreshRateSelector().onModeChangeInitiated();
+        selectorPtr->onModeChangeInitiated();
         mScheduler->onNewVsyncPeriodChangeTimeline(outTimeline);
 
         if (outTimeline.refreshRequired) {
@@ -1518,17 +1539,18 @@
             // TODO(b/255635711): Remove `displayToUpdateImmediately` to `finalizeDisplayModeChange`
             // for all displays. This was only needed when the loop iterated over `mDisplays` rather
             // than `mPhysicalDisplays`.
-            displayToUpdateImmediately = display->getPhysicalId();
+            displayToUpdateImmediately = displayId;
         }
     }
 
     if (displayToUpdateImmediately) {
-        const auto display = getDisplayDeviceLocked(*displayToUpdateImmediately);
-        finalizeDisplayModeChange(*display);
+        const auto displayId = *displayToUpdateImmediately;
+        finalizeDisplayModeChange(displayId);
 
-        const auto desiredModeOpt = display->getDesiredMode();
-        if (desiredModeOpt && display->getActiveMode() == desiredModeOpt->mode) {
-            applyActiveMode(display);
+        const auto desiredModeOpt = mDisplayModeController.getDesiredMode(displayId);
+        if (desiredModeOpt &&
+            mDisplayModeController.getActiveMode(displayId) == desiredModeOpt->mode) {
+            applyActiveMode(displayId);
         }
     }
 }
@@ -2276,8 +2298,10 @@
                         getHwComposer().getComposer()->isVrrSupported() ? data.refreshPeriodNanos
                                                                         : data.vsyncPeriodNanos);
                 ATRACE_FORMAT("%s refresh rate = %d", whence, refreshRate.getIntValue());
-                display->updateRefreshRateOverlayRate(refreshRate, display->getActiveMode().fps,
-                                                      /* showRefreshRate */ true);
+
+                const auto renderRate = mDisplayModeController.getActiveMode(*displayIdOpt).fps;
+                constexpr bool kSetByHwc = true;
+                display->updateRefreshRateOverlayRate(refreshRate, renderRate, kSetByHwc);
             }
         }
     }));
@@ -2585,33 +2609,18 @@
 
     // If a mode set is pending and the fence hasn't fired yet, wait for the next commit.
     if (std::any_of(frameTargets.begin(), frameTargets.end(),
-                    [this](const auto& pair) FTL_FAKE_GUARD(mStateLock)
-                            FTL_FAKE_GUARD(kMainThreadContext) {
-                                if (!pair.second->isFramePending()) return false;
-
-                                if (const auto display = getDisplayDeviceLocked(pair.first)) {
-                                    return display->isModeSetPending();
-                                }
-
-                                return false;
-                            })) {
+                    [this](const auto& pair) FTL_FAKE_GUARD(kMainThreadContext) {
+                        const auto [displayId, target] = pair;
+                        return target->isFramePending() &&
+                                mDisplayModeController.isModeSetPending(displayId);
+                    })) {
         mScheduler->scheduleFrame();
         return false;
     }
 
-    {
-        Mutex::Autolock lock(mStateLock);
-
-        for (const auto [id, target] : frameTargets) {
-            // TODO(b/241285876): This is `nullptr` when the DisplayDevice is about to be removed in
-            // this commit, since the PhysicalDisplay has already been removed. Rather than checking
-            // for `nullptr` below, change Scheduler::onFrameSignal to filter out the FrameTarget of
-            // the removed display.
-            const auto display = getDisplayDeviceLocked(id);
-
-            if (display && display->isModeSetPending()) {
-                finalizeDisplayModeChange(*display);
-            }
+    for (const auto [displayId, _] : frameTargets) {
+        if (mDisplayModeController.isModeSetPending(displayId)) {
+            finalizeDisplayModeChange(displayId);
         }
     }
 
@@ -2646,8 +2655,8 @@
         mPowerAdvisor->setFrameDelay(frameDelay);
         mPowerAdvisor->setTotalFrameTargetWorkDuration(idealSfWorkDuration);
 
-        const auto& display = FTL_FAKE_GUARD(mStateLock, getDefaultDisplayDeviceLocked()).get();
-        const Period idealVsyncPeriod = display->getActiveMode().fps.getPeriod();
+        const Period idealVsyncPeriod =
+                mDisplayModeController.getActiveMode(pacesetterId).fps.getPeriod();
         mPowerAdvisor->updateTargetWorkDuration(idealVsyncPeriod);
     }
 
@@ -2710,9 +2719,10 @@
                                                         ? &mLayerHierarchyBuilder.getHierarchy()
                                                         : nullptr,
                                                 updateAttachedChoreographer);
-        initiateDisplayModeChanges();
     }
 
+    initiateDisplayModeChanges();
+
     updateCursorAsync();
     if (!mustComposite) {
         updateInputFlinger(vsyncId, pacesetterFrameTarget.frameBeginTime());
@@ -3758,7 +3768,8 @@
 
     if (const auto& physical = state.physical) {
         const auto& mode = *physical->activeMode;
-        display->setActiveMode(mode.getId(), mode.getVsyncRate(), mode.getVsyncRate());
+        mDisplayModeController.setActiveMode(physical->id, mode.getId(), mode.getVsyncRate(),
+                                             mode.getVsyncRate());
     }
 
     display->setLayerFilter(makeLayerFilterForDisplay(display->getId(), state.layerStack));
@@ -3937,7 +3948,9 @@
 
             // TODO(b/175678251) Call a listener instead.
             if (currentState.physical->hwcDisplayId == getHwComposer().getPrimaryHwcDisplayId()) {
-                mScheduler->resetPhaseConfiguration(display->getActiveMode().fps);
+                const Fps refreshRate =
+                        mDisplayModeController.getActiveMode(display->getPhysicalId()).fps;
+                mScheduler->resetPhaseConfiguration(refreshRate);
             }
         }
         return;
@@ -7684,9 +7697,10 @@
         if (!display->isRefreshRateOverlayEnabled()) return;
 
         const auto desiredModeIdOpt =
-                display->getDesiredMode().transform([](const display::DisplayModeRequest& request) {
-                    return request.mode.modePtr->getId();
-                });
+                mDisplayModeController.getDesiredMode(display->getPhysicalId())
+                        .transform([](const display::DisplayModeRequest& request) {
+                            return request.mode.modePtr->getId();
+                        });
 
         const bool timerExpired = mKernelIdleTimerEnabled && expired;
 
@@ -8921,20 +8935,26 @@
 
 void SurfaceFlinger::enableRefreshRateOverlay(bool enable) {
     bool setByHwc = getHwComposer().hasCapability(Capability::REFRESH_RATE_CHANGED_CALLBACK_DEBUG);
-    for (const auto& [id, display] : mPhysicalDisplays) {
-        if (display.snapshot().connectionType() == ui::DisplayConnectionType::Internal ||
+    for (const auto& [displayId, physical] : mPhysicalDisplays) {
+        if (physical.snapshot().connectionType() == ui::DisplayConnectionType::Internal ||
             FlagManager::getInstance().refresh_rate_overlay_on_external_display()) {
-            if (const auto device = getDisplayDeviceLocked(id)) {
-                const auto enableOverlay = [&](const bool setByHwc) FTL_FAKE_GUARD(
-                                                   kMainThreadContext) {
-                    device->enableRefreshRateOverlay(enable, setByHwc, mRefreshRateOverlaySpinner,
-                                                     mRefreshRateOverlayRenderRate,
-                                                     mRefreshRateOverlayShowInMiddle);
+            if (const auto display = getDisplayDeviceLocked(displayId)) {
+                const auto enableOverlay = [&](bool setByHwc) FTL_FAKE_GUARD(kMainThreadContext) {
+                    const auto activeMode = mDisplayModeController.getActiveMode(displayId);
+                    const Fps refreshRate = activeMode.modePtr->getVsyncRate();
+                    const Fps renderFps = activeMode.fps;
+
+                    display->enableRefreshRateOverlay(enable, setByHwc, refreshRate, renderFps,
+                                                      mRefreshRateOverlaySpinner,
+                                                      mRefreshRateOverlayRenderRate,
+                                                      mRefreshRateOverlayShowInMiddle);
                 };
+
                 enableOverlay(setByHwc);
                 if (setByHwc) {
                     const auto status =
-                            getHwComposer().setRefreshRateChangedCallbackDebugEnabled(id, enable);
+                            getHwComposer().setRefreshRateChangedCallbackDebugEnabled(displayId,
+                                                                                      enable);
                     if (status != NO_ERROR) {
                         ALOGE("Error %s refresh rate changed callback debug",
                               enable ? "enabling" : "disabling");
@@ -9090,7 +9110,7 @@
     mActiveDisplayId = activeDisplay.getPhysicalId();
     activeDisplay.getCompositionDisplay()->setLayerCachingTexturePoolEnabled(true);
 
-    mScheduler->resetPhaseConfiguration(activeDisplay.getActiveMode().fps);
+    mScheduler->resetPhaseConfiguration(mDisplayModeController.getActiveMode(mActiveDisplayId).fps);
 
     // TODO(b/255635711): Check for pending mode changes on other displays.
     mScheduler->setModeChangePending(false);
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 1230717..ee541c4 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -737,12 +737,12 @@
     status_t setActiveModeFromBackdoor(const sp<display::DisplayToken>&, DisplayModeId, Fps minFps,
                                        Fps maxFps);
 
-    void initiateDisplayModeChanges() REQUIRES(mStateLock, kMainThreadContext);
-    void finalizeDisplayModeChange(DisplayDevice&) REQUIRES(mStateLock, kMainThreadContext);
+    void initiateDisplayModeChanges() REQUIRES(kMainThreadContext) EXCLUDES(mStateLock);
+    void finalizeDisplayModeChange(PhysicalDisplayId) REQUIRES(kMainThreadContext)
+            EXCLUDES(mStateLock);
 
-    // TODO(b/241285191): Replace DisplayDevice with DisplayModeRequest, and move to Scheduler.
-    void dropModeRequest(const sp<DisplayDevice>&) REQUIRES(mStateLock);
-    void applyActiveMode(const sp<DisplayDevice>&) REQUIRES(mStateLock);
+    void dropModeRequest(PhysicalDisplayId) REQUIRES(kMainThreadContext);
+    void applyActiveMode(PhysicalDisplayId) REQUIRES(kMainThreadContext);
 
     // Called on the main thread in response to setPowerMode()
     void setPowerModeInternal(const sp<DisplayDevice>& display, hal::PowerMode mode)
@@ -1098,8 +1098,7 @@
                                const DisplayDeviceState& drawingState)
             REQUIRES(mStateLock, kMainThreadContext);
 
-    void dispatchDisplayModeChangeEvent(PhysicalDisplayId, const scheduler::FrameRateMode&)
-            REQUIRES(mStateLock);
+    void dispatchDisplayModeChangeEvent(PhysicalDisplayId, const scheduler::FrameRateMode&);
 
     /*
      * VSYNC
@@ -1339,9 +1338,7 @@
     display::PhysicalDisplays mPhysicalDisplays GUARDED_BY(mStateLock);
 
     // The inner or outer display for foldables, assuming they have mutually exclusive power states.
-    // Atomic because writes from onActiveDisplayChangedLocked are not always under mStateLock, but
-    // reads from ISchedulerCallback::requestDisplayModes may happen concurrently.
-    std::atomic<PhysicalDisplayId> mActiveDisplayId GUARDED_BY(mStateLock);
+    std::atomic<PhysicalDisplayId> mActiveDisplayId;
 
     display::DisplayModeController mDisplayModeController;
 
diff --git a/services/surfaceflinger/tests/unittests/Android.bp b/services/surfaceflinger/tests/unittests/Android.bp
index 5145e11..98d5754 100644
--- a/services/surfaceflinger/tests/unittests/Android.bp
+++ b/services/surfaceflinger/tests/unittests/Android.bp
@@ -70,9 +70,9 @@
         "DisplayIdGeneratorTest.cpp",
         "DisplayTransactionTest.cpp",
         "DisplayDevice_GetBestColorModeTest.cpp",
-        "DisplayDevice_InitiateModeChange.cpp",
         "DisplayDevice_SetDisplayBrightnessTest.cpp",
         "DisplayDevice_SetProjectionTest.cpp",
+        "DisplayModeControllerTest.cpp",
         "EventThreadTest.cpp",
         "FlagManagerTest.cpp",
         "FpsReporterTest.cpp",
diff --git a/services/surfaceflinger/tests/unittests/DisplayDevice_InitiateModeChange.cpp b/services/surfaceflinger/tests/unittests/DisplayDevice_InitiateModeChange.cpp
deleted file mode 100644
index c463a92..0000000
--- a/services/surfaceflinger/tests/unittests/DisplayDevice_InitiateModeChange.cpp
+++ /dev/null
@@ -1,152 +0,0 @@
-/*
- * Copyright 2021 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.
- */
-
-#undef LOG_TAG
-#define LOG_TAG "LibSurfaceFlingerUnittests"
-
-#include "DisplayTransactionTestHelpers.h"
-#include "mock/MockFrameRateMode.h"
-
-#include <gmock/gmock.h>
-#include <gtest/gtest.h>
-
-#define EXPECT_DISPLAY_MODE_REQUEST(expected, requestOpt)                               \
-    ASSERT_TRUE(requestOpt);                                                            \
-    EXPECT_FRAME_RATE_MODE(expected.mode.modePtr, expected.mode.fps, requestOpt->mode); \
-    EXPECT_EQ(expected.emitEvent, requestOpt->emitEvent)
-
-namespace android {
-namespace {
-
-using FakeDisplayDeviceInjector = TestableSurfaceFlinger::FakeDisplayDeviceInjector;
-using DisplayModeRequest = display::DisplayModeRequest;
-
-class InitiateModeChangeTest : public DisplayTransactionTest {
-public:
-    using Action = DisplayDevice::DesiredModeAction;
-    void SetUp() override {
-        injectFakeBufferQueueFactory();
-        injectFakeNativeWindowSurfaceFactory();
-
-        PrimaryDisplayVariant::setupHwcHotplugCallExpectations(this);
-        PrimaryDisplayVariant::setupFramebufferConsumerBufferQueueCallExpectations(this);
-        PrimaryDisplayVariant::setupFramebufferProducerBufferQueueCallExpectations(this);
-        PrimaryDisplayVariant::setupNativeWindowSurfaceCreationCallExpectations(this);
-        PrimaryDisplayVariant::setupHwcGetActiveConfigCallExpectations(this);
-
-        mFlinger.onComposerHalHotplugEvent(PrimaryDisplayVariant::HWC_DISPLAY_ID,
-                                           DisplayHotplugEvent::CONNECTED);
-        mFlinger.configureAndCommit();
-
-        mDisplay = PrimaryDisplayVariant::makeFakeExistingDisplayInjector(this)
-                           .setDisplayModes(makeModes(kMode60, kMode90, kMode120), kModeId60)
-                           .inject();
-    }
-
-protected:
-    sp<DisplayDevice> mDisplay;
-
-    static constexpr DisplayModeId kModeId60{0};
-    static constexpr DisplayModeId kModeId90{1};
-    static constexpr DisplayModeId kModeId120{2};
-
-    static inline const ftl::NonNull<DisplayModePtr> kMode60 =
-            ftl::as_non_null(createDisplayMode(kModeId60, 60_Hz));
-    static inline const ftl::NonNull<DisplayModePtr> kMode90 =
-            ftl::as_non_null(createDisplayMode(kModeId90, 90_Hz));
-    static inline const ftl::NonNull<DisplayModePtr> kMode120 =
-            ftl::as_non_null(createDisplayMode(kModeId120, 120_Hz));
-
-    static inline const DisplayModeRequest kDesiredMode30{{30_Hz, kMode60}, .emitEvent = false};
-    static inline const DisplayModeRequest kDesiredMode60{{60_Hz, kMode60}, .emitEvent = true};
-    static inline const DisplayModeRequest kDesiredMode90{{90_Hz, kMode90}, .emitEvent = false};
-    static inline const DisplayModeRequest kDesiredMode120{{120_Hz, kMode120}, .emitEvent = true};
-};
-
-TEST_F(InitiateModeChangeTest, setDesiredModeToActiveMode) {
-    EXPECT_EQ(Action::None, mDisplay->setDesiredMode(DisplayModeRequest(kDesiredMode60)));
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-}
-
-TEST_F(InitiateModeChangeTest, setDesiredMode) {
-    EXPECT_EQ(Action::InitiateDisplayModeSwitch,
-              mDisplay->setDesiredMode(DisplayModeRequest(kDesiredMode90)));
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDisplay->getDesiredMode());
-
-    EXPECT_EQ(Action::None, mDisplay->setDesiredMode(DisplayModeRequest(kDesiredMode120)));
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode120, mDisplay->getDesiredMode());
-}
-
-TEST_F(InitiateModeChangeTest, clearDesiredMode) {
-    EXPECT_EQ(Action::InitiateDisplayModeSwitch,
-              mDisplay->setDesiredMode(DisplayModeRequest(kDesiredMode90)));
-    EXPECT_TRUE(mDisplay->getDesiredMode());
-
-    mDisplay->clearDesiredMode();
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-}
-
-TEST_F(InitiateModeChangeTest, initiateModeChange) REQUIRES(kMainThreadContext) {
-    EXPECT_EQ(Action::InitiateDisplayModeSwitch,
-              mDisplay->setDesiredMode(DisplayModeRequest(kDesiredMode90)));
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDisplay->getDesiredMode());
-
-    const hal::VsyncPeriodChangeConstraints constraints{
-            .desiredTimeNanos = systemTime(),
-            .seamlessRequired = false,
-    };
-    hal::VsyncPeriodChangeTimeline timeline;
-    EXPECT_TRUE(mDisplay->initiateModeChange(*mDisplay->getDesiredMode(), constraints, timeline));
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDisplay->getPendingMode());
-
-    mDisplay->clearDesiredMode();
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-}
-
-TEST_F(InitiateModeChangeTest, initiateRenderRateSwitch) {
-    EXPECT_EQ(Action::InitiateRenderRateSwitch,
-              mDisplay->setDesiredMode(DisplayModeRequest(kDesiredMode30)));
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-}
-
-TEST_F(InitiateModeChangeTest, initiateDisplayModeSwitch) FTL_FAKE_GUARD(kMainThreadContext) {
-    EXPECT_EQ(Action::InitiateDisplayModeSwitch,
-              mDisplay->setDesiredMode(DisplayModeRequest(kDesiredMode90)));
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDisplay->getDesiredMode());
-
-    const hal::VsyncPeriodChangeConstraints constraints{
-            .desiredTimeNanos = systemTime(),
-            .seamlessRequired = false,
-    };
-    hal::VsyncPeriodChangeTimeline timeline;
-    EXPECT_TRUE(mDisplay->initiateModeChange(*mDisplay->getDesiredMode(), constraints, timeline));
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDisplay->getPendingMode());
-
-    EXPECT_EQ(Action::None, mDisplay->setDesiredMode(DisplayModeRequest(kDesiredMode120)));
-    ASSERT_TRUE(mDisplay->getDesiredMode());
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode120, mDisplay->getDesiredMode());
-
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDisplay->getPendingMode());
-
-    EXPECT_TRUE(mDisplay->initiateModeChange(*mDisplay->getDesiredMode(), constraints, timeline));
-    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode120, mDisplay->getPendingMode());
-
-    mDisplay->clearDesiredMode();
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-}
-
-} // namespace
-} // namespace android
diff --git a/services/surfaceflinger/tests/unittests/DisplayModeControllerTest.cpp b/services/surfaceflinger/tests/unittests/DisplayModeControllerTest.cpp
new file mode 100644
index 0000000..d971150
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/DisplayModeControllerTest.cpp
@@ -0,0 +1,234 @@
+/*
+ * Copyright 2024 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.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "LibSurfaceFlingerUnittests"
+
+#include "Display/DisplayModeController.h"
+#include "Display/DisplaySnapshot.h"
+#include "DisplayHardware/HWComposer.h"
+#include "DisplayIdentificationTestHelpers.h"
+#include "FpsOps.h"
+#include "mock/DisplayHardware/MockComposer.h"
+#include "mock/DisplayHardware/MockDisplayMode.h"
+#include "mock/MockFrameRateMode.h"
+
+#include <ftl/fake_guard.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#define EXPECT_DISPLAY_MODE_REQUEST(expected, requestOpt)                               \
+    ASSERT_TRUE(requestOpt);                                                            \
+    EXPECT_FRAME_RATE_MODE(expected.mode.modePtr, expected.mode.fps, requestOpt->mode); \
+    EXPECT_EQ(expected.emitEvent, requestOpt->emitEvent)
+
+namespace android::display {
+namespace {
+
+namespace hal = android::hardware::graphics::composer::hal;
+
+using testing::_;
+using testing::DoAll;
+using testing::Return;
+using testing::SetArgPointee;
+
+class DisplayModeControllerTest : public testing::Test {
+public:
+    using Action = DisplayModeController::DesiredModeAction;
+
+    void SetUp() override {
+        mDmc.setHwComposer(mComposer.get());
+        mDmc.setActiveModeListener(
+                [this](PhysicalDisplayId displayId, Fps vsyncRate, Fps renderFps) {
+                    mActiveModeListener.Call(displayId, vsyncRate, renderFps);
+                });
+
+        constexpr uint8_t kPort = 111;
+        EXPECT_CALL(*mComposerHal, getDisplayIdentificationData(kHwcDisplayId, _, _))
+                .WillOnce(DoAll(SetArgPointee<1>(kPort), SetArgPointee<2>(getInternalEdid()),
+                                Return(hal::Error::NONE)));
+
+        EXPECT_CALL(*mComposerHal, setClientTargetSlotCount(kHwcDisplayId));
+        EXPECT_CALL(*mComposerHal,
+                    setVsyncEnabled(kHwcDisplayId, hal::IComposerClient::Vsync::DISABLE));
+        EXPECT_CALL(*mComposerHal, onHotplugConnect(kHwcDisplayId));
+
+        const auto infoOpt = mComposer->onHotplug(kHwcDisplayId, hal::Connection::CONNECTED);
+        ASSERT_TRUE(infoOpt);
+
+        mDisplayId = infoOpt->id;
+        mDisplaySnapshotOpt.emplace(mDisplayId, ui::DisplayConnectionType::Internal,
+                                    makeModes(kMode60, kMode90, kMode120), ui::ColorModes{},
+                                    std::nullopt);
+
+        ftl::FakeGuard guard(kMainThreadContext);
+        mDmc.registerDisplay(*mDisplaySnapshotOpt, kModeId60,
+                             scheduler::RefreshRateSelector::Config{});
+    }
+
+protected:
+    hal::VsyncPeriodChangeConstraints expectModeSet(const DisplayModeRequest& request,
+                                                    hal::VsyncPeriodChangeTimeline& timeline,
+                                                    bool subsequent = false) {
+        EXPECT_CALL(*mComposerHal,
+                    isSupported(Hwc2::Composer::OptionalFeature::RefreshRateSwitching))
+                .WillOnce(Return(true));
+
+        if (!subsequent) {
+            EXPECT_CALL(*mComposerHal, getDisplayConnectionType(kHwcDisplayId, _))
+                    .WillOnce(DoAll(SetArgPointee<1>(
+                                            hal::IComposerClient::DisplayConnectionType::INTERNAL),
+                                    Return(hal::V2_4::Error::NONE)));
+        }
+
+        const hal::VsyncPeriodChangeConstraints constraints{
+                .desiredTimeNanos = systemTime(),
+                .seamlessRequired = false,
+        };
+
+        const hal::HWConfigId hwcModeId = request.mode.modePtr->getHwcId();
+
+        EXPECT_CALL(*mComposerHal,
+                    setActiveConfigWithConstraints(kHwcDisplayId, hwcModeId, constraints, _))
+                .WillOnce(DoAll(SetArgPointee<3>(timeline), Return(hal::V2_4::Error::NONE)));
+
+        return constraints;
+    }
+
+    static constexpr hal::HWDisplayId kHwcDisplayId = 1234;
+
+    Hwc2::mock::Composer* mComposerHal = new testing::StrictMock<Hwc2::mock::Composer>();
+    const std::unique_ptr<HWComposer> mComposer{
+            std::make_unique<impl::HWComposer>(std::unique_ptr<Hwc2::Composer>(mComposerHal))};
+
+    testing::MockFunction<void(PhysicalDisplayId, Fps, Fps)> mActiveModeListener;
+
+    DisplayModeController mDmc;
+
+    PhysicalDisplayId mDisplayId;
+    std::optional<DisplaySnapshot> mDisplaySnapshotOpt;
+
+    static constexpr DisplayModeId kModeId60{0};
+    static constexpr DisplayModeId kModeId90{1};
+    static constexpr DisplayModeId kModeId120{2};
+
+    static inline const ftl::NonNull<DisplayModePtr> kMode60 =
+            ftl::as_non_null(mock::createDisplayMode(kModeId60, 60_Hz));
+    static inline const ftl::NonNull<DisplayModePtr> kMode90 =
+            ftl::as_non_null(mock::createDisplayMode(kModeId90, 90_Hz));
+    static inline const ftl::NonNull<DisplayModePtr> kMode120 =
+            ftl::as_non_null(mock::createDisplayMode(kModeId120, 120_Hz));
+
+    static inline const DisplayModeRequest kDesiredMode30{{30_Hz, kMode60}, .emitEvent = false};
+    static inline const DisplayModeRequest kDesiredMode60{{60_Hz, kMode60}, .emitEvent = true};
+    static inline const DisplayModeRequest kDesiredMode90{{90_Hz, kMode90}, .emitEvent = false};
+    static inline const DisplayModeRequest kDesiredMode120{{120_Hz, kMode120}, .emitEvent = true};
+};
+
+TEST_F(DisplayModeControllerTest, setDesiredModeToActiveMode) {
+    EXPECT_CALL(mActiveModeListener, Call(_, _, _)).Times(0);
+
+    EXPECT_EQ(Action::None, mDmc.setDesiredMode(mDisplayId, DisplayModeRequest(kDesiredMode60)));
+    EXPECT_FALSE(mDmc.getDesiredMode(mDisplayId));
+}
+
+TEST_F(DisplayModeControllerTest, setDesiredMode) {
+    // Called because setDesiredMode resets the render rate to the active refresh rate.
+    EXPECT_CALL(mActiveModeListener, Call(mDisplayId, 60_Hz, 60_Hz)).Times(1);
+
+    EXPECT_EQ(Action::InitiateDisplayModeSwitch,
+              mDmc.setDesiredMode(mDisplayId, DisplayModeRequest(kDesiredMode90)));
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDmc.getDesiredMode(mDisplayId));
+
+    // No action since a mode switch has already been initiated.
+    EXPECT_EQ(Action::None, mDmc.setDesiredMode(mDisplayId, DisplayModeRequest(kDesiredMode120)));
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode120, mDmc.getDesiredMode(mDisplayId));
+}
+
+TEST_F(DisplayModeControllerTest, clearDesiredMode) {
+    // Called because setDesiredMode resets the render rate to the active refresh rate.
+    EXPECT_CALL(mActiveModeListener, Call(mDisplayId, 60_Hz, 60_Hz)).Times(1);
+
+    EXPECT_EQ(Action::InitiateDisplayModeSwitch,
+              mDmc.setDesiredMode(mDisplayId, DisplayModeRequest(kDesiredMode90)));
+    EXPECT_TRUE(mDmc.getDesiredMode(mDisplayId));
+
+    mDmc.clearDesiredMode(mDisplayId);
+    EXPECT_FALSE(mDmc.getDesiredMode(mDisplayId));
+}
+
+TEST_F(DisplayModeControllerTest, initiateModeChange) REQUIRES(kMainThreadContext) {
+    // Called because setDesiredMode resets the render rate to the active refresh rate.
+    EXPECT_CALL(mActiveModeListener, Call(mDisplayId, 60_Hz, 60_Hz)).Times(1);
+
+    EXPECT_EQ(Action::InitiateDisplayModeSwitch,
+              mDmc.setDesiredMode(mDisplayId, DisplayModeRequest(kDesiredMode90)));
+
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDmc.getDesiredMode(mDisplayId));
+    auto modeRequest = kDesiredMode90;
+
+    hal::VsyncPeriodChangeTimeline timeline;
+    const auto constraints = expectModeSet(modeRequest, timeline);
+
+    EXPECT_TRUE(mDmc.initiateModeChange(mDisplayId, std::move(modeRequest), constraints, timeline));
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDmc.getPendingMode(mDisplayId));
+
+    mDmc.clearDesiredMode(mDisplayId);
+    EXPECT_FALSE(mDmc.getDesiredMode(mDisplayId));
+}
+
+TEST_F(DisplayModeControllerTest, initiateRenderRateSwitch) {
+    EXPECT_CALL(mActiveModeListener, Call(mDisplayId, 60_Hz, 30_Hz)).Times(1);
+
+    EXPECT_EQ(Action::InitiateRenderRateSwitch,
+              mDmc.setDesiredMode(mDisplayId, DisplayModeRequest(kDesiredMode30)));
+    EXPECT_FALSE(mDmc.getDesiredMode(mDisplayId));
+}
+
+TEST_F(DisplayModeControllerTest, initiateDisplayModeSwitch) FTL_FAKE_GUARD(kMainThreadContext) {
+    // Called because setDesiredMode resets the render rate to the active refresh rate.
+    EXPECT_CALL(mActiveModeListener, Call(mDisplayId, 60_Hz, 60_Hz)).Times(1);
+
+    EXPECT_EQ(Action::InitiateDisplayModeSwitch,
+              mDmc.setDesiredMode(mDisplayId, DisplayModeRequest(kDesiredMode90)));
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDmc.getDesiredMode(mDisplayId));
+    auto modeRequest = kDesiredMode90;
+
+    hal::VsyncPeriodChangeTimeline timeline;
+    auto constraints = expectModeSet(modeRequest, timeline);
+
+    EXPECT_TRUE(mDmc.initiateModeChange(mDisplayId, std::move(modeRequest), constraints, timeline));
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDmc.getPendingMode(mDisplayId));
+
+    // No action since a mode switch has already been initiated.
+    EXPECT_EQ(Action::None, mDmc.setDesiredMode(mDisplayId, DisplayModeRequest(kDesiredMode120)));
+
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode90, mDmc.getPendingMode(mDisplayId));
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode120, mDmc.getDesiredMode(mDisplayId));
+    modeRequest = kDesiredMode120;
+
+    constexpr bool kSubsequent = true;
+    constraints = expectModeSet(modeRequest, timeline, kSubsequent);
+
+    EXPECT_TRUE(mDmc.initiateModeChange(mDisplayId, std::move(modeRequest), constraints, timeline));
+    EXPECT_DISPLAY_MODE_REQUEST(kDesiredMode120, mDmc.getPendingMode(mDisplayId));
+
+    mDmc.clearDesiredMode(mDisplayId);
+    EXPECT_FALSE(mDmc.getDesiredMode(mDisplayId));
+}
+
+} // namespace
+} // namespace android::display
diff --git a/services/surfaceflinger/tests/unittests/SurfaceFlinger_DisplayModeSwitching.cpp b/services/surfaceflinger/tests/unittests/SurfaceFlinger_DisplayModeSwitching.cpp
index 078b4fe..0c3e875 100644
--- a/services/surfaceflinger/tests/unittests/SurfaceFlinger_DisplayModeSwitching.cpp
+++ b/services/surfaceflinger/tests/unittests/SurfaceFlinger_DisplayModeSwitching.cpp
@@ -76,6 +76,7 @@
         mDisplay = PrimaryDisplayVariant::makeFakeExistingDisplayInjector(this)
                            .setRefreshRateSelector(std::move(selectorPtr))
                            .inject(std::move(vsyncController), std::move(vsyncTracker));
+        mDisplayId = mDisplay->getPhysicalId();
 
         // isVsyncPeriodSwitchSupported should return true, otherwise the SF's HWC proxy
         // will call setActiveConfig instead of setActiveConfigWithConstraints.
@@ -112,7 +113,11 @@
 protected:
     void setupScheduler(std::shared_ptr<scheduler::RefreshRateSelector>);
 
+    auto& dmc() { return mFlinger.mutableDisplayModeController(); }
+
     sp<DisplayDevice> mDisplay, mOuterDisplay;
+    PhysicalDisplayId mDisplayId;
+
     mock::EventThread* mAppEventThread;
 
     static constexpr DisplayModeId kModeId60{0};
@@ -167,17 +172,17 @@
 TEST_F(DisplayModeSwitchingTest, changeRefreshRateOnActiveDisplayWithRefreshRequired) {
     ftl::FakeGuard guard(kMainThreadContext);
 
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId60);
+    EXPECT_FALSE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId60);
 
     mFlinger.onActiveDisplayChanged(nullptr, *mDisplay);
 
     mFlinger.setDesiredDisplayModeSpecs(mDisplay->getDisplayToken().promote(),
                                         mock::createDisplayModeSpecs(kModeId90, false, 0, 120));
 
-    ASSERT_TRUE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getDesiredMode()->mode.modePtr->getId(), kModeId90);
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId60);
+    ASSERT_TRUE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getDesiredMode(mDisplayId)->mode.modePtr->getId(), kModeId90);
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId60);
 
     // Verify that next commit will call setActiveConfigWithConstraints in HWC
     const VsyncPeriodChangeTimeline timeline{.refreshRequired = true};
@@ -187,8 +192,8 @@
 
     Mock::VerifyAndClearExpectations(mComposer);
 
-    EXPECT_TRUE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId60);
+    EXPECT_TRUE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId60);
 
     // Verify that the next commit will complete the mode change and send
     // a onModeChanged event to the framework.
@@ -198,23 +203,23 @@
     mFlinger.commit();
     Mock::VerifyAndClearExpectations(mAppEventThread);
 
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId90);
+    EXPECT_FALSE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId90);
 }
 
 TEST_F(DisplayModeSwitchingTest, changeRefreshRateOnActiveDisplayWithoutRefreshRequired) {
     ftl::FakeGuard guard(kMainThreadContext);
 
-    EXPECT_FALSE(mDisplay->getDesiredMode());
+    EXPECT_FALSE(dmc().getDesiredMode(mDisplayId));
 
     mFlinger.onActiveDisplayChanged(nullptr, *mDisplay);
 
     mFlinger.setDesiredDisplayModeSpecs(mDisplay->getDisplayToken().promote(),
                                         mock::createDisplayModeSpecs(kModeId90, true, 0, 120));
 
-    ASSERT_TRUE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getDesiredMode()->mode.modePtr->getId(), kModeId90);
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId60);
+    ASSERT_TRUE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getDesiredMode(mDisplayId)->mode.modePtr->getId(), kModeId90);
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId60);
 
     // Verify that next commit will call setActiveConfigWithConstraints in HWC
     // and complete the mode change.
@@ -226,8 +231,8 @@
 
     mFlinger.commit();
 
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId90);
+    EXPECT_FALSE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId90);
 }
 
 TEST_F(DisplayModeSwitchingTest, twoConsecutiveSetDesiredDisplayModeSpecs) {
@@ -236,8 +241,8 @@
     // Test that if we call setDesiredDisplayModeSpecs while a previous mode change
     // is still being processed the later call will be respected.
 
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId60);
+    EXPECT_FALSE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId60);
 
     mFlinger.onActiveDisplayChanged(nullptr, *mDisplay);
 
@@ -252,46 +257,45 @@
     mFlinger.setDesiredDisplayModeSpecs(mDisplay->getDisplayToken().promote(),
                                         mock::createDisplayModeSpecs(kModeId120, false, 0, 180));
 
-    ASSERT_TRUE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getDesiredMode()->mode.modePtr->getId(), kModeId120);
+    ASSERT_TRUE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getDesiredMode(mDisplayId)->mode.modePtr->getId(), kModeId120);
 
     EXPECT_SET_ACTIVE_CONFIG(PrimaryDisplayVariant::HWC_DISPLAY_ID, kModeId120);
 
     mFlinger.commit();
 
-    ASSERT_TRUE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getDesiredMode()->mode.modePtr->getId(), kModeId120);
+    ASSERT_TRUE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getDesiredMode(mDisplayId)->mode.modePtr->getId(), kModeId120);
 
     mFlinger.commit();
 
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId120);
+    EXPECT_FALSE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId120);
 }
 
 TEST_F(DisplayModeSwitchingTest, changeResolutionOnActiveDisplayWithoutRefreshRequired) {
     ftl::FakeGuard guard(kMainThreadContext);
 
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId60);
+    EXPECT_FALSE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId60);
 
     mFlinger.onActiveDisplayChanged(nullptr, *mDisplay);
 
     mFlinger.setDesiredDisplayModeSpecs(mDisplay->getDisplayToken().promote(),
                                         mock::createDisplayModeSpecs(kModeId90_4K, false, 0, 120));
 
-    ASSERT_TRUE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getDesiredMode()->mode.modePtr->getId(), kModeId90_4K);
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId60);
+    ASSERT_TRUE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getDesiredMode(mDisplayId)->mode.modePtr->getId(), kModeId90_4K);
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId60);
 
     // Verify that next commit will call setActiveConfigWithConstraints in HWC
     // and complete the mode change.
     const VsyncPeriodChangeTimeline timeline{.refreshRequired = false};
     EXPECT_SET_ACTIVE_CONFIG(PrimaryDisplayVariant::HWC_DISPLAY_ID, kModeId90_4K);
 
-    EXPECT_CALL(*mAppEventThread, onHotplugReceived(mDisplay->getPhysicalId(), true));
+    EXPECT_CALL(*mAppEventThread, onHotplugReceived(mDisplayId, true));
 
-    // Misc expecations. We don't need to enforce these method calls, but since the helper methods
-    // already set expectations we should add new ones here, otherwise the test will fail.
+    // Override expectations set up by PrimaryDisplayVariant.
     EXPECT_CALL(*mConsumer,
                 setDefaultBufferSize(static_cast<uint32_t>(kResolution4K.getWidth()),
                                      static_cast<uint32_t>(kResolution4K.getHeight())))
@@ -304,31 +308,28 @@
     injectFakeNativeWindowSurfaceFactory();
     PrimaryDisplayVariant::setupNativeWindowSurfaceCreationCallExpectations(this);
 
-    const auto displayToken = mDisplay->getDisplayToken().promote();
-
     mFlinger.commit();
 
-    // The DisplayDevice will be destroyed and recreated,
-    // so we need to update with the new instance.
-    mDisplay = mFlinger.getDisplay(displayToken);
-
-    EXPECT_FALSE(mDisplay->getDesiredMode());
-    EXPECT_EQ(mDisplay->getActiveMode().modePtr->getId(), kModeId90_4K);
+    EXPECT_FALSE(dmc().getDesiredMode(mDisplayId));
+    EXPECT_EQ(dmc().getActiveMode(mDisplayId).modePtr->getId(), kModeId90_4K);
 }
 
 MATCHER_P2(ModeSwitchingTo, flinger, modeId, "") {
-    if (!arg->getDesiredMode()) {
+    const auto displayId = arg->getPhysicalId();
+    auto& dmc = flinger->mutableDisplayModeController();
+
+    if (!dmc.getDesiredMode(displayId)) {
         *result_listener << "No desired mode";
         return false;
     }
 
-    if (arg->getDesiredMode()->mode.modePtr->getId() != modeId) {
+    if (dmc.getDesiredMode(displayId)->mode.modePtr->getId() != modeId) {
         *result_listener << "Unexpected desired mode " << ftl::to_underlying(modeId);
         return false;
     }
 
     // VsyncModulator should react to mode switches on the pacesetter display.
-    if (arg->getPhysicalId() == flinger->scheduler()->pacesetterDisplayId() &&
+    if (displayId == flinger->scheduler()->pacesetterDisplayId() &&
         !flinger->scheduler()->vsyncModulator().isVsyncConfigEarly()) {
         *result_listener << "VsyncModulator did not shift to early phase";
         return false;
@@ -337,8 +338,10 @@
     return true;
 }
 
-MATCHER_P(ModeSettledTo, modeId, "") {
-    if (const auto desiredOpt = arg->getDesiredMode()) {
+MATCHER_P2(ModeSettledTo, dmc, modeId, "") {
+    const auto displayId = arg->getPhysicalId();
+
+    if (const auto desiredOpt = dmc->getDesiredMode(displayId)) {
         *result_listener << "Unsettled desired mode "
                          << ftl::to_underlying(desiredOpt->mode.modePtr->getId());
         return false;
@@ -346,7 +349,7 @@
 
     ftl::FakeGuard guard(kMainThreadContext);
 
-    if (arg->getActiveMode().modePtr->getId() != modeId) {
+    if (dmc->getActiveMode(displayId).modePtr->getId() != modeId) {
         *result_listener << "Settled to unexpected active mode " << ftl::to_underlying(modeId);
         return false;
     }
@@ -367,14 +370,14 @@
     EXPECT_TRUE(innerDisplay->isPoweredOn());
     EXPECT_FALSE(outerDisplay->isPoweredOn());
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId60));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId120));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId60));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId120));
 
     mFlinger.setPowerModeInternal(outerDisplay, hal::PowerMode::OFF);
     mFlinger.setPowerModeInternal(innerDisplay, hal::PowerMode::ON);
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId60));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId120));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId60));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId120));
 
     EXPECT_EQ(NO_ERROR,
               mFlinger.setDesiredDisplayModeSpecs(innerDisplay->getDisplayToken().promote(),
@@ -400,14 +403,14 @@
 
     mFlinger.commit();
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId90));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId60));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId90));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId60));
 
     mFlinger.setPowerModeInternal(innerDisplay, hal::PowerMode::OFF);
     mFlinger.setPowerModeInternal(outerDisplay, hal::PowerMode::ON);
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId90));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId60));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId90));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId60));
 
     EXPECT_EQ(NO_ERROR,
               mFlinger.setDesiredDisplayModeSpecs(innerDisplay->getDisplayToken().promote(),
@@ -420,12 +423,12 @@
     mFlinger.commit();
 
     EXPECT_THAT(innerDisplay, ModeSwitchingTo(&mFlinger, kModeId60));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId60));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId60));
 
     mFlinger.commit();
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId60));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId60));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId60));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId60));
 }
 
 TEST_F(DisplayModeSwitchingTest, innerAndOuterDisplay) {
@@ -440,14 +443,14 @@
     EXPECT_TRUE(innerDisplay->isPoweredOn());
     EXPECT_FALSE(outerDisplay->isPoweredOn());
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId60));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId120));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId60));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId120));
 
     mFlinger.setPowerModeInternal(innerDisplay, hal::PowerMode::ON);
     mFlinger.setPowerModeInternal(outerDisplay, hal::PowerMode::ON);
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId60));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId120));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId60));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId120));
 
     EXPECT_EQ(NO_ERROR,
               mFlinger.setDesiredDisplayModeSpecs(innerDisplay->getDisplayToken().promote(),
@@ -473,13 +476,13 @@
 
     mFlinger.commit();
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId90));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId60));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId90));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId60));
 }
 
 TEST_F(DisplayModeSwitchingTest, powerOffDuringModeSet) {
     EXPECT_TRUE(mDisplay->isPoweredOn());
-    EXPECT_THAT(mDisplay, ModeSettledTo(kModeId60));
+    EXPECT_THAT(mDisplay, ModeSettledTo(&dmc(), kModeId60));
 
     EXPECT_EQ(NO_ERROR,
               mFlinger.setDesiredDisplayModeSpecs(mDisplay->getDisplayToken().promote(),
@@ -502,7 +505,7 @@
 
     mFlinger.commit();
 
-    EXPECT_THAT(mDisplay, ModeSettledTo(kModeId90));
+    EXPECT_THAT(mDisplay, ModeSettledTo(&dmc(), kModeId90));
 }
 
 TEST_F(DisplayModeSwitchingTest, powerOffDuringConcurrentModeSet) {
@@ -518,14 +521,14 @@
     EXPECT_TRUE(innerDisplay->isPoweredOn());
     EXPECT_FALSE(outerDisplay->isPoweredOn());
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId60));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId120));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId60));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId120));
 
     mFlinger.setPowerModeInternal(innerDisplay, hal::PowerMode::ON);
     mFlinger.setPowerModeInternal(outerDisplay, hal::PowerMode::ON);
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId60));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId120));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId60));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId120));
 
     EXPECT_EQ(NO_ERROR,
               mFlinger.setDesiredDisplayModeSpecs(innerDisplay->getDisplayToken().promote(),
@@ -555,8 +558,8 @@
 
     mFlinger.commit();
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId90));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId60));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId90));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId60));
 
     mFlinger.setPowerModeInternal(innerDisplay, hal::PowerMode::OFF);
     mFlinger.setPowerModeInternal(outerDisplay, hal::PowerMode::ON);
@@ -570,13 +573,13 @@
 
     mFlinger.commit();
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId90));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId90));
     EXPECT_THAT(outerDisplay, ModeSwitchingTo(&mFlinger, kModeId120));
 
     mFlinger.commit();
 
-    EXPECT_THAT(innerDisplay, ModeSettledTo(kModeId90));
-    EXPECT_THAT(outerDisplay, ModeSettledTo(kModeId120));
+    EXPECT_THAT(innerDisplay, ModeSettledTo(&dmc(), kModeId90));
+    EXPECT_THAT(outerDisplay, ModeSettledTo(&dmc(), kModeId120));
 }
 
 } // namespace
diff --git a/services/surfaceflinger/tests/unittests/SurfaceFlinger_SetupNewDisplayDeviceInternalTest.cpp b/services/surfaceflinger/tests/unittests/SurfaceFlinger_SetupNewDisplayDeviceInternalTest.cpp
index 1bae5ff..933d03d 100644
--- a/services/surfaceflinger/tests/unittests/SurfaceFlinger_SetupNewDisplayDeviceInternalTest.cpp
+++ b/services/surfaceflinger/tests/unittests/SurfaceFlinger_SetupNewDisplayDeviceInternalTest.cpp
@@ -232,7 +232,9 @@
     // Invocation
 
     DisplayDeviceState state;
-    if constexpr (constexpr auto connectionType = Case::Display::CONNECTION_TYPE::value) {
+
+    constexpr auto kConnectionTypeOpt = Case::Display::CONNECTION_TYPE::value;
+    if constexpr (kConnectionTypeOpt) {
         const auto displayId = PhysicalDisplayId::tryCast(Case::Display::DISPLAY_ID::get());
         ASSERT_TRUE(displayId);
         const auto hwcDisplayId = Case::Display::HWC_DISPLAY_ID_OPT::value;
@@ -257,7 +259,7 @@
 
         const auto it = mFlinger.mutablePhysicalDisplays()
                                 .emplace_or_replace(*displayId, displayToken, *displayId,
-                                                    *connectionType, makeModes(activeMode),
+                                                    *kConnectionTypeOpt, makeModes(activeMode),
                                                     std::move(colorModes), std::nullopt)
                                 .first;
 
@@ -291,9 +293,12 @@
     EXPECT_EQ(Case::Display::DISPLAY_FLAGS & DisplayDevice::eReceivesInput,
               device->receivesInput());
 
-    if constexpr (Case::Display::CONNECTION_TYPE::value) {
+    if constexpr (kConnectionTypeOpt) {
         ftl::FakeGuard guard(kMainThreadContext);
-        EXPECT_EQ(Case::Display::HWC_ACTIVE_CONFIG_ID, device->getActiveMode().modePtr->getHwcId());
+        EXPECT_EQ(Case::Display::HWC_ACTIVE_CONFIG_ID,
+                  mFlinger.mutableDisplayModeController()
+                          .getActiveMode(device->getPhysicalId())
+                          .modePtr->getHwcId());
     }
 }
 
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index 8c72a7d..007383b 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -191,6 +191,8 @@
     void setupComposer(std::unique_ptr<Hwc2::Composer> composer) {
         mFlinger->mCompositionEngine->setHwComposer(
                 std::make_unique<impl::HWComposer>(std::move(composer)));
+        mFlinger->mDisplayModeController.setHwComposer(
+                &mFlinger->mCompositionEngine->getHwComposer());
     }
 
     void setupPowerAdvisor(std::unique_ptr<Hwc2::PowerAdvisor> powerAdvisor) {
@@ -1055,7 +1057,6 @@
 
             auto& modes = mDisplayModes;
             auto& activeModeId = mActiveModeId;
-            std::optional<Fps> refreshRateOpt;
 
             DisplayDeviceState state;
             state.isSecure = mCreationArgs.isSecure;
@@ -1093,7 +1094,9 @@
 
                 const auto activeModeOpt = modes.get(activeModeId);
                 LOG_ALWAYS_FATAL_IF(!activeModeOpt);
-                refreshRateOpt = activeModeOpt->get()->getPeakFps();
+
+                // Save a copy for use after `modes` is consumed.
+                const Fps refreshRate = activeModeOpt->get()->getPeakFps();
 
                 state.physical = {.id = *physicalId,
                                   .hwcDisplayId = *mHwcDisplayId,
@@ -1109,6 +1112,9 @@
                         .registerDisplay(*physicalId, it->second.snapshot(),
                                          mCreationArgs.refreshRateSelector);
 
+                mFlinger.mutableDisplayModeController().setActiveMode(*physicalId, activeModeId,
+                                                                      refreshRate, refreshRate);
+
                 if (mFlinger.scheduler() && mSchedulerRegistration) {
                     mFlinger.scheduler()->registerDisplay(*physicalId,
                                                           mCreationArgs.refreshRateSelector,
@@ -1120,10 +1126,6 @@
             sp<DisplayDevice> display = sp<DisplayDevice>::make(mCreationArgs);
             mFlinger.mutableDisplays().emplace_or_replace(mDisplayToken, display);
 
-            if (refreshRateOpt) {
-                display->setActiveMode(activeModeId, *refreshRateOpt, *refreshRateOpt);
-            }
-
             mFlinger.mutableCurrentState().displays.add(mDisplayToken, state);
             mFlinger.mutableDrawingState().displays.add(mDisplayToken, state);