Snap for 5892339 from fcf2c201ad8d353f6268a6c6f0363c7751f34a7c to qt-qpr1-release

Change-Id: I7b1a6b5a1b7fd1709d3f581b68269f63b342d41d

4 files changed, 37 insertions, 11 deletions

diff --git a/services/surfaceflinger/Scheduler/LayerInfo.h b/services/surfaceflinger/Scheduler/LayerInfo.h
index a7337817e3..17afddac28 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.h
+++ b/services/surfaceflinger/Scheduler/LayerInfo.h
@@ -109,7 +109,7 @@ class LayerInfo {
         bool isLowActivityLayer() const {
             // We want to make sure that we received more than two frames from the layer
             // in order to check low activity.
-            if (mElements.size() < 2) {
+            if (mElements.size() < scheduler::LOW_ACTIVITY_BUFFERS + 1) {
                 return false;
             }
 
@@ -118,7 +118,8 @@ class LayerInfo {
             // Check the frame before last to determine whether there is low activity.
             // If that frame is older than LOW_ACTIVITY_EPSILON_NS, the layer is sending
             // infrequent updates.
-            if (mElements.at(mElements.size() - 2) < obsoleteEpsilon) {
+            if (mElements.at(mElements.size() - (scheduler::LOW_ACTIVITY_BUFFERS + 1)) <
+                obsoleteEpsilon) {
                 return true;
             }
 
diff --git a/services/surfaceflinger/Scheduler/SchedulerUtils.h b/services/surfaceflinger/Scheduler/SchedulerUtils.h
index ced1899109..ac10f83ad9 100644
--- a/services/surfaceflinger/Scheduler/SchedulerUtils.h
+++ b/services/surfaceflinger/Scheduler/SchedulerUtils.h
@@ -42,9 +42,11 @@ static constexpr uint32_t HWC2_SCREEN_OFF_CONFIG_ID = 0xffffffff;
 // or waiting idle in messaging app, when cursor is blinking.
 static constexpr std::chrono::nanoseconds OBSOLETE_TIME_EPSILON_NS = 1200ms;
 
-// Layer is considered low activity if the buffers come more than LOW_ACTIVITY_EPSILON_NS
-// apart. This is helping SF to vote for lower refresh rates when there is not activity
+// Layer is considered low activity if the LOW_ACTIVITY_BUFFERS buffers come more than
+// LOW_ACTIVITY_EPSILON_NS  apart.
+// This is helping SF to vote for lower refresh rates when there is not activity
 // in screen.
+static constexpr int LOW_ACTIVITY_BUFFERS = 2;
 static constexpr std::chrono::nanoseconds LOW_ACTIVITY_EPSILON_NS = 250ms;
 
 // Calculates the statistical mean (average) in the data structure (array, vector). The
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index d91b0e7db7..23b399f838 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -358,6 +358,11 @@ SurfaceFlinger::SurfaceFlinger(Factory& factory) : SurfaceFlinger(factory, SkipI
     mPropagateBackpressure = !atoi(value);
     ALOGI_IF(!mPropagateBackpressure, "Disabling backpressure propagation");
 
+    property_get("debug.sf.enable_gl_backpressure", value, "0");
+    mPropagateBackpressureClientComposition = atoi(value);
+    ALOGI_IF(mPropagateBackpressureClientComposition,
+             "Enabling backpressure propagation for Client Composition");
+
     property_get("debug.sf.enable_hwc_vds", value, "0");
     mUseHwcVirtualDisplays = atoi(value);
     ALOGI_IF(mUseHwcVirtualDisplays, "Enabling HWC virtual displays");
@@ -1676,7 +1681,8 @@ void SurfaceFlinger::updateVrFlinger() {
     setTransactionFlags(eDisplayTransactionNeeded);
 }
 
-bool SurfaceFlinger::previousFrameMissed() NO_THREAD_SAFETY_ANALYSIS {
+bool SurfaceFlinger::previousFrameMissed(int graceTimeMs) NO_THREAD_SAFETY_ANALYSIS {
+    ATRACE_CALL();
     // We are storing the last 2 present fences. If sf's phase offset is to be
     // woken up before the actual vsync but targeting the next vsync, we need to check
     // fence N-2
@@ -1685,7 +1691,15 @@ bool SurfaceFlinger::previousFrameMissed() NO_THREAD_SAFETY_ANALYSIS {
             ? mPreviousPresentFences[0]
             : mPreviousPresentFences[1];
 
-    return fence != Fence::NO_FENCE && (fence->getStatus() == Fence::Status::Unsignaled);
+    if (fence == Fence::NO_FENCE) {
+        return false;
+    }
+
+    if (graceTimeMs > 0 && fence->getStatus() == Fence::Status::Unsignaled) {
+        fence->wait(graceTimeMs);
+    }
+
+    return (fence->getStatus() == Fence::Status::Unsignaled);
 }
 
 void SurfaceFlinger::populateExpectedPresentTime() NO_THREAD_SAFETY_ANALYSIS {
@@ -1708,7 +1722,15 @@ void SurfaceFlinger::onMessageReceived(int32_t what) NO_THREAD_SAFETY_ANALYSIS {
             // seeing this same value.
             populateExpectedPresentTime();
 
-            bool frameMissed = previousFrameMissed();
+            // When Backpressure propagation is enabled we want to give a small grace period
+            // for the present fence to fire instead of just giving up on this frame to handle cases
+            // where present fence is just about to get signaled.
+            const int graceTimeForPresentFenceMs =
+                    (mPropagateBackpressure &&
+                     (mPropagateBackpressureClientComposition || !mHadClientComposition))
+                    ? 1
+                    : 0;
+            bool frameMissed = previousFrameMissed(graceTimeForPresentFenceMs);
             bool hwcFrameMissed = mHadDeviceComposition && frameMissed;
             bool gpuFrameMissed = mHadClientComposition && frameMissed;
             ATRACE_INT("FrameMissed", static_cast<int>(frameMissed));
@@ -1737,9 +1759,9 @@ void SurfaceFlinger::onMessageReceived(int32_t what) NO_THREAD_SAFETY_ANALYSIS {
                 break;
             }
 
-            // For now, only propagate backpressure when missing a hwc frame.
-            if (hwcFrameMissed && !gpuFrameMissed) {
-                if (mPropagateBackpressure) {
+            if (frameMissed && mPropagateBackpressure) {
+                if ((hwcFrameMissed && !gpuFrameMissed) ||
+                    mPropagateBackpressureClientComposition) {
                     signalLayerUpdate();
                     break;
                 }
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 74882f3909..2718e0e860 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -851,7 +851,7 @@ private:
         return hwcDisplayId ? getHwComposer().toPhysicalDisplayId(*hwcDisplayId) : std::nullopt;
     }
 
-    bool previousFrameMissed();
+    bool previousFrameMissed(int graceTimeMs = 0);
     void setVsyncEnabledInHWC(DisplayId displayId, HWC2::Vsync enabled);
 
     /*
@@ -1023,6 +1023,7 @@ private:
     volatile nsecs_t mDebugInTransaction = 0;
     bool mForceFullDamage = false;
     bool mPropagateBackpressure = true;
+    bool mPropagateBackpressureClientComposition = false;
     std::unique_ptr<SurfaceInterceptor> mInterceptor;
     SurfaceTracing mTracing{*this};
     bool mTracingEnabled = false;