Merge changes from topic "b:140112642:5" into qt-surfaceflinger-dev

* changes:
  SurfaceFlinger: clamp frame refresh duration to min refresh duration
  SurfaceFlinger: calculate expected present once
  [SurfaceFlinger] Exclude first vsync duration from period calculation
  SurfaceFlinger: tune LayerHistory to be less aggressive
  [SurfaceFlinger] Don't touch hw vsync in DEFAULT RR with kernel timeout
  SurfaceFlinger: add display power state timer
diff --git a/services/surfaceflinger/Scheduler/DispSync.cpp b/services/surfaceflinger/Scheduler/DispSync.cpp
index 83fd42b..0c94052 100644
--- a/services/surfaceflinger/Scheduler/DispSync.cpp
+++ b/services/surfaceflinger/Scheduler/DispSync.cpp
@@ -668,7 +668,13 @@
         nsecs_t durationSum = 0;
         nsecs_t minDuration = INT64_MAX;
         nsecs_t maxDuration = 0;
-        for (size_t i = 1; i < mNumResyncSamples; i++) {
+        // We skip the first 2 samples because the first vsync duration on some
+        // devices may be much more inaccurate than on other devices, e.g. due
+        // to delays in ramping up from a power collapse. By doing so this
+        // actually increases the accuracy of the DispSync model even though
+        // we're effectively relying on fewer sample points.
+        static constexpr size_t numSamplesSkipped = 2;
+        for (size_t i = numSamplesSkipped; i < mNumResyncSamples; i++) {
             size_t idx = (mFirstResyncSample + i) % MAX_RESYNC_SAMPLES;
             size_t prev = (idx + MAX_RESYNC_SAMPLES - 1) % MAX_RESYNC_SAMPLES;
             nsecs_t duration = mResyncSamples[idx] - mResyncSamples[prev];
@@ -679,15 +685,14 @@
 
         // Exclude the min and max from the average
         durationSum -= minDuration + maxDuration;
-        mPeriod = durationSum / (mNumResyncSamples - 3);
+        mPeriod = durationSum / (mNumResyncSamples - numSamplesSkipped - 2);
 
         ALOGV("[%s] mPeriod = %" PRId64, mName, ns2us(mPeriod));
 
         double sampleAvgX = 0;
         double sampleAvgY = 0;
         double scale = 2.0 * M_PI / double(mPeriod);
-        // Intentionally skip the first sample
-        for (size_t i = 1; i < mNumResyncSamples; i++) {
+        for (size_t i = numSamplesSkipped; i < mNumResyncSamples; i++) {
             size_t idx = (mFirstResyncSample + i) % MAX_RESYNC_SAMPLES;
             nsecs_t sample = mResyncSamples[idx] - mReferenceTime;
             double samplePhase = double(sample % mPeriod) * scale;
@@ -695,8 +700,8 @@
             sampleAvgY += sin(samplePhase);
         }
 
-        sampleAvgX /= double(mNumResyncSamples - 1);
-        sampleAvgY /= double(mNumResyncSamples - 1);
+        sampleAvgX /= double(mNumResyncSamples - numSamplesSkipped);
+        sampleAvgY /= double(mNumResyncSamples - numSamplesSkipped);
 
         mPhase = nsecs_t(atan2(sampleAvgY, sampleAvgX) / scale);
 
diff --git a/services/surfaceflinger/Scheduler/LayerInfo.cpp b/services/surfaceflinger/Scheduler/LayerInfo.cpp
index 38afb7e..6e5df12 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.cpp
+++ b/services/surfaceflinger/Scheduler/LayerInfo.cpp
@@ -43,7 +43,7 @@
     mLastPresentTime = lastPresentTime;
     // Ignore time diff that are too high - those are stale values
     if (timeDiff > OBSOLETE_TIME_EPSILON_NS.count()) return;
-    const nsecs_t refreshDuration = (timeDiff > 0) ? timeDiff : mMinRefreshDuration;
+    const nsecs_t refreshDuration = std::max(timeDiff, mMinRefreshDuration);
     const int fps = 1e9f / refreshDuration;
     mRefreshRateHistory.insertRefreshRate(fps);
 }
diff --git a/services/surfaceflinger/Scheduler/LayerInfo.h b/services/surfaceflinger/Scheduler/LayerInfo.h
index 66df9dc..a733781 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.h
+++ b/services/surfaceflinger/Scheduler/LayerInfo.h
@@ -129,8 +129,8 @@
 
     private:
         std::deque<nsecs_t> mElements;
-        static constexpr size_t HISTORY_SIZE = 10;
-        static constexpr std::chrono::nanoseconds HISTORY_TIME = 500ms;
+        static constexpr size_t HISTORY_SIZE = 90;
+        static constexpr std::chrono::nanoseconds HISTORY_TIME = 1s;
     };
 
 public:
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index cfdbd91..a194106 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -76,6 +76,7 @@
     mSupportKernelTimer = support_kernel_idle_timer(false);
 
     mSetTouchTimerMs = set_touch_timer_ms(0);
+    mSetDisplayPowerTimerMs = set_display_power_timer_ms(0);
 
     char value[PROPERTY_VALUE_MAX];
     property_get("debug.sf.set_idle_timer_ms", value, "0");
@@ -110,10 +111,22 @@
                                                        [this] { expiredTouchTimerCallback(); });
         mTouchTimer->start();
     }
+
+    if (mSetDisplayPowerTimerMs > 0) {
+        mDisplayPowerTimer =
+                std::make_unique<scheduler::IdleTimer>(std::chrono::milliseconds(
+                                                               mSetDisplayPowerTimerMs),
+                                                       [this] { resetDisplayPowerTimerCallback(); },
+                                                       [this] {
+                                                           expiredDisplayPowerTimerCallback();
+                                                       });
+        mDisplayPowerTimer->start();
+    }
 }
 
 Scheduler::~Scheduler() {
     // Ensure the IdleTimer thread is joined before we start destroying state.
+    mDisplayPowerTimer.reset();
     mTouchTimer.reset();
     mIdleTimer.reset();
 }
@@ -380,11 +393,17 @@
 }
 
 void Scheduler::setChangeRefreshRateCallback(
-        const ChangeRefreshRateCallback& changeRefreshRateCallback) {
+        const ChangeRefreshRateCallback&& changeRefreshRateCallback) {
     std::lock_guard<std::mutex> lock(mCallbackLock);
     mChangeRefreshRateCallback = changeRefreshRateCallback;
 }
 
+void Scheduler::setGetCurrentRefreshRateTypeCallback(
+        const GetCurrentRefreshRateTypeCallback&& getCurrentRefreshRateTypeCallback) {
+    std::lock_guard<std::mutex> lock(mCallbackLock);
+    mGetCurrentRefreshRateTypeCallback = getCurrentRefreshRateTypeCallback;
+}
+
 void Scheduler::setGetVsyncPeriodCallback(const GetVsyncPeriod&& getVsyncPeriod) {
     std::lock_guard<std::mutex> lock(mCallbackLock);
     mGetVsyncPeriod = getVsyncPeriod;
@@ -419,41 +438,75 @@
     mLayerHistory.clearHistory();
 }
 
+void Scheduler::setDisplayPowerState(bool normal) {
+    {
+        std::lock_guard<std::mutex> lock(mFeatureStateLock);
+        mIsDisplayPowerStateNormal = normal;
+    }
+
+    if (mDisplayPowerTimer) {
+        mDisplayPowerTimer->reset();
+    }
+
+    // Display Power event will boost the refresh rate to performance.
+    // Clear Layer History to get fresh FPS detection
+    mLayerHistory.clearHistory();
+}
+
 void Scheduler::resetTimerCallback() {
-    timerChangeRefreshRate(IdleTimerState::RESET);
+    handleTimerStateChanged(&mCurrentIdleTimerState, IdleTimerState::RESET, false);
     ATRACE_INT("ExpiredIdleTimer", 0);
 }
 
 void Scheduler::resetKernelTimerCallback() {
     ATRACE_INT("ExpiredKernelIdleTimer", 0);
     std::lock_guard<std::mutex> lock(mCallbackLock);
-    if (mGetVsyncPeriod) {
-        resyncToHardwareVsync(true, mGetVsyncPeriod());
+    if (mGetVsyncPeriod && mGetCurrentRefreshRateTypeCallback) {
+        // If we're not in performance mode then the kernel timer shouldn't do
+        // anything, as the refresh rate during DPU power collapse will be the
+        // same.
+        if (mGetCurrentRefreshRateTypeCallback() == Scheduler::RefreshRateType::PERFORMANCE) {
+            resyncToHardwareVsync(true, mGetVsyncPeriod());
+        }
     }
 }
 
 void Scheduler::expiredTimerCallback() {
-    timerChangeRefreshRate(IdleTimerState::EXPIRED);
+    handleTimerStateChanged(&mCurrentIdleTimerState, IdleTimerState::EXPIRED, false);
     ATRACE_INT("ExpiredIdleTimer", 1);
 }
 
 void Scheduler::resetTouchTimerCallback() {
-    // We do not notify the applications about config changes when idle timer is reset.
-    touchChangeRefreshRate(TouchState::ACTIVE);
+    handleTimerStateChanged(&mCurrentTouchState, TouchState::ACTIVE, true);
     ATRACE_INT("TouchState", 1);
 }
 
 void Scheduler::expiredTouchTimerCallback() {
-    // We do not notify the applications about config changes when idle timer expires.
-    touchChangeRefreshRate(TouchState::INACTIVE);
+    handleTimerStateChanged(&mCurrentTouchState, TouchState::INACTIVE, true);
     ATRACE_INT("TouchState", 0);
 }
 
+void Scheduler::resetDisplayPowerTimerCallback() {
+    handleTimerStateChanged(&mDisplayPowerTimerState, DisplayPowerTimerState::RESET, true);
+    ATRACE_INT("ExpiredDisplayPowerTimer", 0);
+}
+
+void Scheduler::expiredDisplayPowerTimerCallback() {
+    handleTimerStateChanged(&mDisplayPowerTimerState, DisplayPowerTimerState::EXPIRED, true);
+    ATRACE_INT("ExpiredDisplayPowerTimer", 1);
+}
+
 void Scheduler::expiredKernelTimerCallback() {
+    std::lock_guard<std::mutex> lock(mCallbackLock);
     ATRACE_INT("ExpiredKernelIdleTimer", 1);
-    // Disable HW Vsync if the timer expired, as we don't need it
-    // enabled if we're not pushing frames.
-    disableHardwareVsync(false);
+    if (mGetCurrentRefreshRateTypeCallback) {
+        if (mGetCurrentRefreshRateTypeCallback() != Scheduler::RefreshRateType::PERFORMANCE) {
+            // Disable HW Vsync if the timer expired, as we don't need it
+            // enabled if we're not pushing frames, and if we're in PERFORMANCE
+            // mode then we'll need to re-update the DispSync model anyways.
+            disableHardwareVsync(false);
+        }
+    }
 }
 
 std::string Scheduler::doDump() {
@@ -463,39 +516,23 @@
     return stream.str();
 }
 
-void Scheduler::timerChangeRefreshRate(IdleTimerState idleTimerState) {
-    RefreshRateType newRefreshRateType;
-    {
-        std::lock_guard<std::mutex> lock(mFeatureStateLock);
-        if (mCurrentIdleTimerState == idleTimerState) {
-            return;
-        }
-        mCurrentIdleTimerState = idleTimerState;
-        newRefreshRateType = calculateRefreshRateType();
-        if (mRefreshRateType == newRefreshRateType) {
-            return;
-        }
-        mRefreshRateType = newRefreshRateType;
-    }
-    changeRefreshRate(newRefreshRateType, ConfigEvent::None);
-}
-
-void Scheduler::touchChangeRefreshRate(TouchState touchState) {
+template <class T>
+void Scheduler::handleTimerStateChanged(T* currentState, T newState, bool eventOnContentDetection) {
     ConfigEvent event = ConfigEvent::None;
     RefreshRateType newRefreshRateType;
     {
         std::lock_guard<std::mutex> lock(mFeatureStateLock);
-        if (mCurrentTouchState == touchState) {
+        if (*currentState == newState) {
             return;
         }
-        mCurrentTouchState = touchState;
+        *currentState = newState;
         newRefreshRateType = calculateRefreshRateType();
         if (mRefreshRateType == newRefreshRateType) {
             return;
         }
         mRefreshRateType = newRefreshRateType;
-        // Send an event in case that content detection is on as touch has a higher priority
-        if (mCurrentContentFeatureState == ContentFeatureState::CONTENT_DETECTION_ON) {
+        if (eventOnContentDetection &&
+            mCurrentContentFeatureState == ContentFeatureState::CONTENT_DETECTION_ON) {
             event = ConfigEvent::Changed;
         }
     }
@@ -508,6 +545,12 @@
         return RefreshRateType::DEFAULT;
     }
 
+    // If Display Power is not in normal operation we want to be in performance mode.
+    // When coming back to normal mode, a grace period is given with DisplayPowerTimer
+    if (!mIsDisplayPowerStateNormal || mDisplayPowerTimerState == DisplayPowerTimerState::RESET) {
+        return RefreshRateType::PERFORMANCE;
+    }
+
     // As long as touch is active we want to be in performance mode
     if (mCurrentTouchState == TouchState::ACTIVE) {
         return RefreshRateType::PERFORMANCE;
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index eaad37c..5d8bb4c 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -49,6 +49,7 @@
     }
 
     using RefreshRateType = scheduler::RefreshRateConfigs::RefreshRateType;
+    using GetCurrentRefreshRateTypeCallback = std::function<RefreshRateType()>;
     using ChangeRefreshRateCallback = std::function<void(RefreshRateType, ConfigEvent)>;
     using GetVsyncPeriod = std::function<nsecs_t()>;
 
@@ -165,7 +166,9 @@
     // Updates FPS based on the most content presented.
     void updateFpsBasedOnContent();
     // Callback that gets invoked when Scheduler wants to change the refresh rate.
-    void setChangeRefreshRateCallback(const ChangeRefreshRateCallback& changeRefreshRateCallback);
+    void setChangeRefreshRateCallback(const ChangeRefreshRateCallback&& changeRefreshRateCallback);
+    void setGetCurrentRefreshRateTypeCallback(
+            const GetCurrentRefreshRateTypeCallback&& getCurrentRefreshRateType);
     void setGetVsyncPeriodCallback(const GetVsyncPeriod&& getVsyncPeriod);
 
     // Returns whether idle timer is enabled or not
@@ -177,6 +180,9 @@
     // Function that resets the touch timer.
     void notifyTouchEvent();
 
+    // Function that sets whether display power mode is normal or not.
+    void setDisplayPowerState(bool normal);
+
     // Returns relevant information about Scheduler for dumpsys purposes.
     std::string doDump();
 
@@ -197,6 +203,7 @@
     enum class ContentFeatureState { CONTENT_DETECTION_ON, CONTENT_DETECTION_OFF };
     enum class IdleTimerState { EXPIRED, RESET };
     enum class TouchState { INACTIVE, ACTIVE };
+    enum class DisplayPowerTimerState { EXPIRED, RESET };
 
     // Creates a connection on the given EventThread and forwards the given callbacks.
     sp<EventThreadConnection> createConnectionInternal(EventThread*, ResyncCallback&&,
@@ -221,12 +228,15 @@
     void resetTouchTimerCallback();
     // Function that is called when the touch timer expires.
     void expiredTouchTimerCallback();
+    // Function that is called when the display power timer resets.
+    void resetDisplayPowerTimerCallback();
+    // Function that is called when the display power timer expires.
+    void expiredDisplayPowerTimerCallback();
     // Sets vsync period.
     void setVsyncPeriod(const nsecs_t period);
-    // Idle timer feature's function to change the refresh rate.
-    void timerChangeRefreshRate(IdleTimerState idleTimerState);
-    // Touch timer feature's function to change the refresh rate.
-    void touchChangeRefreshRate(TouchState touchState);
+    // handles various timer features to change the refresh rate.
+    template <class T>
+    void handleTimerStateChanged(T* currentState, T newState, bool eventOnContentDetection);
     // Calculate the new refresh rate type
     RefreshRateType calculateRefreshRateType() REQUIRES(mFeatureStateLock);
     // Acquires a lock and calls the ChangeRefreshRateCallback() with given parameters.
@@ -282,7 +292,12 @@
     int64_t mSetTouchTimerMs = 0;
     std::unique_ptr<scheduler::IdleTimer> mTouchTimer;
 
+    // Timer used to monitor display power mode.
+    int64_t mSetDisplayPowerTimerMs = 0;
+    std::unique_ptr<scheduler::IdleTimer> mDisplayPowerTimer;
+
     std::mutex mCallbackLock;
+    GetCurrentRefreshRateTypeCallback mGetCurrentRefreshRateTypeCallback GUARDED_BY(mCallbackLock);
     ChangeRefreshRateCallback mChangeRefreshRateCallback GUARDED_BY(mCallbackLock);
     GetVsyncPeriod mGetVsyncPeriod GUARDED_BY(mCallbackLock);
 
@@ -293,9 +308,12 @@
             ContentFeatureState::CONTENT_DETECTION_OFF;
     IdleTimerState mCurrentIdleTimerState GUARDED_BY(mFeatureStateLock) = IdleTimerState::RESET;
     TouchState mCurrentTouchState GUARDED_BY(mFeatureStateLock) = TouchState::INACTIVE;
+    DisplayPowerTimerState mDisplayPowerTimerState GUARDED_BY(mFeatureStateLock) =
+            DisplayPowerTimerState::EXPIRED;
     uint32_t mContentRefreshRate GUARDED_BY(mFeatureStateLock);
     RefreshRateType mRefreshRateType GUARDED_BY(mFeatureStateLock);
     bool mIsHDRContent GUARDED_BY(mFeatureStateLock) = false;
+    bool mIsDisplayPowerStateNormal GUARDED_BY(mFeatureStateLock) = true;
 
     const scheduler::RefreshRateConfigs& mRefreshRateConfigs;
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index a2c87bd..42188d1 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -715,6 +715,24 @@
                 Mutex::Autolock lock(mStateLock);
                 setRefreshRateTo(type, event);
             });
+    mScheduler->setGetCurrentRefreshRateTypeCallback([this] {
+        Mutex::Autolock lock(mStateLock);
+        const auto display = getDefaultDisplayDeviceLocked();
+        if (!display) {
+            // If we don't have a default display the fallback to the default
+            // refresh rate type
+            return RefreshRateType::DEFAULT;
+        }
+
+        const int configId = display->getActiveConfig();
+        for (const auto& [type, refresh] : mRefreshRateConfigs.getRefreshRates()) {
+            if (refresh && refresh->configId == configId) {
+                return type;
+            }
+        }
+        // This should never happen, but just gracefully fallback to default.
+        return RefreshRateType::DEFAULT;
+    });
     mScheduler->setGetVsyncPeriodCallback([this] {
         Mutex::Autolock lock(mStateLock);
         return getVsyncPeriod();
@@ -1047,6 +1065,7 @@
         desiredActiveConfigChangeDone();
         return false;
     }
+
     mUpcomingActiveConfig = desiredActiveConfig;
     const auto displayId = display->getId();
     LOG_ALWAYS_FATAL_IF(!displayId);
@@ -1669,22 +1688,26 @@
     return fence != Fence::NO_FENCE && (fence->getStatus() == Fence::Status::Unsignaled);
 }
 
-nsecs_t SurfaceFlinger::getExpectedPresentTime() NO_THREAD_SAFETY_ANALYSIS {
+void SurfaceFlinger::populateExpectedPresentTime() NO_THREAD_SAFETY_ANALYSIS {
     DisplayStatInfo stats;
     mScheduler->getDisplayStatInfo(&stats);
     const nsecs_t presentTime = mScheduler->getDispSyncExpectedPresentTime();
     // Inflate the expected present time if we're targetting the next vsync.
-    const nsecs_t correctedTime =
+    mExpectedPresentTime =
             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) {
         case MessageQueue::INVALIDATE: {
+            // calculate the expected present time once and use the cached
+            // value throughout this frame to make sure all layers are
+            // seeing this same value.
+            populateExpectedPresentTime();
+
             bool frameMissed = previousFrameMissed();
             bool hwcFrameMissed = mHadDeviceComposition && frameMissed;
             bool gpuFrameMissed = mHadClientComposition && frameMissed;
@@ -4540,6 +4563,7 @@
     if (display->isPrimary()) {
         mTimeStats->setPowerMode(mode);
         mRefreshRateStats.setPowerMode(mode);
+        mScheduler->setDisplayPowerState(mode == HWC_POWER_MODE_NORMAL);
     }
 
     ALOGD("Finished setting power mode %d on display %s", mode, to_string(*displayId).c_str());
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index a8057aa..ec0b7c5 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -301,10 +301,11 @@
     // TODO: this should be made accessible only to MessageQueue
     void onMessageReceived(int32_t what);
 
-    // Returns the expected present time for this frame.
+    // populates the expected present time for this frame.
     // When we are in negative offsets, we perform a correction so that the
     // predicted vsync for the *next* frame is used instead.
-    nsecs_t getExpectedPresentTime();
+    void populateExpectedPresentTime();
+    nsecs_t getExpectedPresentTime() const { return mExpectedPresentTime; }
 
     // for debugging only
     // TODO: this should be made accessible only to HWComposer
@@ -1184,6 +1185,8 @@
     // Flags to capture the state of Vsync in HWC
     HWC2::Vsync mHWCVsyncState = HWC2::Vsync::Disable;
     HWC2::Vsync mHWCVsyncPendingState = HWC2::Vsync::Disable;
+
+    nsecs_t mExpectedPresentTime;
 };
 
 } // namespace android
diff --git a/services/surfaceflinger/SurfaceFlingerProperties.cpp b/services/surfaceflinger/SurfaceFlingerProperties.cpp
index 2b33ba1..3eedb67 100644
--- a/services/surfaceflinger/SurfaceFlingerProperties.cpp
+++ b/services/surfaceflinger/SurfaceFlingerProperties.cpp
@@ -234,6 +234,14 @@
     return defaultValue;
 }
 
+int32_t set_display_power_timer_ms(int32_t defaultValue) {
+    auto temp = SurfaceFlingerProperties::set_display_power_timer_ms();
+    if (temp.has_value()) {
+        return *temp;
+    }
+    return defaultValue;
+}
+
 bool use_smart_90_for_video(bool defaultValue) {
     auto temp = SurfaceFlingerProperties::use_smart_90_for_video();
     if (temp.has_value()) {
diff --git a/services/surfaceflinger/SurfaceFlingerProperties.h b/services/surfaceflinger/SurfaceFlingerProperties.h
index 1964ccd..68986f7 100644
--- a/services/surfaceflinger/SurfaceFlingerProperties.h
+++ b/services/surfaceflinger/SurfaceFlingerProperties.h
@@ -74,6 +74,8 @@
 
 int32_t set_touch_timer_ms(int32_t defaultValue);
 
+int32_t set_display_power_timer_ms(int32_t defaultValue);
+
 bool use_smart_90_for_video(bool defaultValue);
 
 bool enable_protected_contents(bool defaultValue);
diff --git a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
index decabd5..c77137a 100644
--- a/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
+++ b/services/surfaceflinger/sysprop/SurfaceFlingerProperties.sysprop
@@ -309,6 +309,18 @@
     prop_name: "ro.surface_flinger.set_touch_timer_ms"
 }
 
+# setDisplayPowerTimerMs indicates what is considered a timeout in milliseconds for Scheduler.
+# This value is used by the Scheduler to trigger display power inactivity callbacks that will
+# keep the display in peak refresh rate as long as display power is not in normal mode.
+# Setting this property to 0 means there is no timer.
+prop {
+    api_name: "set_display_power_timer_ms"
+    type: Integer
+    scope: System
+    access: Readonly
+    prop_name: "ro.surface_flinger.set_display_power_timer_ms"
+}
+
 # useSmart90ForVideo indicates whether Scheduler should detect content FPS, and try to adjust the
 # screen refresh rate based on that.
 prop {
diff --git a/services/surfaceflinger/sysprop/api/system-current.txt b/services/surfaceflinger/sysprop/api/system-current.txt
index 6ae3ac1..794c1d6 100644
--- a/services/surfaceflinger/sysprop/api/system-current.txt
+++ b/services/surfaceflinger/sysprop/api/system-current.txt
@@ -17,6 +17,7 @@
     method public static java.util.Optional<java.lang.Long> present_time_offset_from_vsync_ns();
     method public static java.util.Optional<android.sysprop.SurfaceFlingerProperties.primary_display_orientation_values> primary_display_orientation();
     method public static java.util.Optional<java.lang.Boolean> running_without_sync_framework();
+    method public static java.util.Optional<java.lang.Integer> set_display_power_timer_ms();
     method public static java.util.Optional<java.lang.Integer> set_idle_timer_ms();
     method public static java.util.Optional<java.lang.Integer> set_touch_timer_ms();
     method public static java.util.Optional<java.lang.Boolean> start_graphics_allocator_service();
diff --git a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
index 7ec9066..8e7440c 100644
--- a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
+++ b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
@@ -27,6 +27,15 @@
 
     static constexpr float MIN_REFRESH_RATE = 30.f;
     static constexpr float MAX_REFRESH_RATE = 90.f;
+    static constexpr auto RELEVANT_FRAME_THRESHOLD = 90u;
+    static constexpr uint64_t THIRTY_FPS_INTERVAL = 33'333'333;
+
+    void forceRelevancy(const std::unique_ptr<LayerHistory::LayerHandle>& testLayer) {
+        mLayerHistory->setVisibility(testLayer, true);
+        for (auto i = 0u; i < RELEVANT_FRAME_THRESHOLD; i++) {
+            mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
+        }
+    };
 };
 
 LayerHistoryTest::LayerHistoryTest() {
@@ -39,24 +48,18 @@
     std::unique_ptr<LayerHistory::LayerHandle> testLayer =
             mLayerHistory->createLayer("TestLayer", MIN_REFRESH_RATE, MAX_REFRESH_RATE);
     mLayerHistory->setVisibility(testLayer, true);
+    for (auto i = 0u; i < RELEVANT_FRAME_THRESHOLD; i++) {
+        EXPECT_FLOAT_EQ(0.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
+        mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
+    }
 
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    EXPECT_FLOAT_EQ(0.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
-
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    // This is still 0, because the layer is not considered recently active if it
-    // has been present in less than 10 frames.
-    EXPECT_FLOAT_EQ(0.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
-    // This should be MAX_REFRESH_RATE as we have more than 10 samples
-    EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
+    // Add a few more. This time we should get MAX refresh rate as the layer
+    // becomes relevant
+    static constexpr auto A_FEW = 10;
+    for (auto i = 0u; i < A_FEW; i++) {
+        EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
+        mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
+    }
 }
 
 TEST_F(LayerHistoryTest, oneHDRLayer) {
@@ -79,8 +82,9 @@
     mLayerHistory->setVisibility(test30FpsLayer, true);
 
     nsecs_t startTime = systemTime();
-    for (int i = 0; i < 31; i++) {
-        mLayerHistory->insert(test30FpsLayer, startTime + (i * 33333333), false /*isHDR*/);
+    for (int i = 0; i < RELEVANT_FRAME_THRESHOLD; i++) {
+        mLayerHistory->insert(test30FpsLayer, startTime + (i * THIRTY_FPS_INTERVAL),
+                              false /*isHDR*/);
     }
 
     EXPECT_FLOAT_EQ(30.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
@@ -98,19 +102,21 @@
     mLayerHistory->setVisibility(testLayer2, true);
 
     nsecs_t startTime = systemTime();
-    for (int i = 0; i < 10; i++) {
+    for (int i = 0; i < RELEVANT_FRAME_THRESHOLD; i++) {
         mLayerHistory->insert(testLayer, 0, false /*isHDR*/);
     }
     EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
 
     startTime = systemTime();
-    for (int i = 0; i < 10; i++) {
-        mLayerHistory->insert(test30FpsLayer, startTime + (i * 33333333), false /*isHDR*/);
+    for (int i = 0; i < RELEVANT_FRAME_THRESHOLD; i++) {
+        mLayerHistory->insert(test30FpsLayer, startTime + (i * THIRTY_FPS_INTERVAL),
+                              false /*isHDR*/);
     }
     EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
 
-    for (int i = 10; i < 30; i++) {
-        mLayerHistory->insert(test30FpsLayer, startTime + (i * 33333333), false /*isHDR*/);
+    for (int i = 10; i < RELEVANT_FRAME_THRESHOLD; i++) {
+        mLayerHistory->insert(test30FpsLayer, startTime + (i * THIRTY_FPS_INTERVAL),
+                              false /*isHDR*/);
     }
     EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
 
@@ -122,8 +128,10 @@
     EXPECT_FLOAT_EQ(MAX_REFRESH_RATE, mLayerHistory->getDesiredRefreshRateAndHDR().first);
     // 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*/);
+
+    mLayerHistory->insert(test30FpsLayer,
+                          startTime + (RELEVANT_FRAME_THRESHOLD * THIRTY_FPS_INTERVAL),
+                          false /*isHDR*/);
     EXPECT_FLOAT_EQ(30.f, mLayerHistory->getDesiredRefreshRateAndHDR().first);
 }