commit df59f4744c0672cc69dad72b230a757c1e4be116
author Vishnu Nair <vishnun@google.com> Fri May 17 16:51:33 2024 +0000
committer Ady Abraham <adyabr@google.com> Fri May 17 21:35:24 2024 +0000
tree 8258c077d6a9dee4926a2313ee063f40e2f1a3ed
parent ef7f5d11c09ff046e4cf5420aaf07c8baa01aded

SF: avoid a composition cycle when the FrameRate votes updates

SF would still do a composition if the display mode changes, but
it is not required for every frame rate vote change.

Bug: 339759346
Test: android.platform.test.scenario.gmail.OpenCloseComposeEmailMicrobenchmark#testOpenCloseComposeEmail
Change-Id: Ia01a13b1a167b3a0a67cf7be3db5e64b9405580a

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 66385d8..f13b4ce 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1411,11 +1411,12 @@
     }
 }
 
-void SurfaceFlinger::initiateDisplayModeChanges() {
+bool SurfaceFlinger::initiateDisplayModeChanges() {
     ATRACE_CALL();
 
     std::optional<PhysicalDisplayId> displayToUpdateImmediately;
 
+    bool mustComposite = false;
     for (const auto& [id, physical] : mPhysicalDisplays) {
         const auto display = getDisplayDeviceLocked(id);
         if (!display) continue;
@@ -1472,7 +1473,11 @@
         mScheduler->onNewVsyncPeriodChangeTimeline(outTimeline);
 
         if (outTimeline.refreshRequired) {
-            scheduleComposite(FrameHint::kNone);
+            if (FlagManager::getInstance().vrr_bugfix_24q4()) {
+                mustComposite = true;
+            } else {
+                scheduleComposite(FrameHint::kNone);
+            }
         } else {
             // TODO(b/255635711): Remove `displayToUpdateImmediately` to `finalizeDisplayModeChange`
             // for all displays. This was only needed when the loop iterated over `mDisplays` rather
@@ -1490,6 +1495,8 @@
             applyActiveMode(display);
         }
     }
+
+    return mustComposite;
 }
 
 void SurfaceFlinger::disableExpensiveRendering() {
@@ -2439,7 +2446,12 @@
         mUpdateAttachedChoreographer = true;
     }
     outTransactionsAreEmpty = mLayerLifecycleManager.getGlobalChanges().get() == 0;
-    mustComposite |= mLayerLifecycleManager.getGlobalChanges().get() != 0;
+    if (FlagManager::getInstance().vrr_bugfix_24q4()) {
+        mustComposite |= mLayerLifecycleManager.getGlobalChanges().test(
+                frontend::RequestedLayerState::Changes::RequiresComposition);
+    } else {
+        mustComposite |= mLayerLifecycleManager.getGlobalChanges().get() != 0;
+    }
 
     bool newDataLatched = false;
     ATRACE_NAME("DisplayCallbackAndStatsUpdates");
@@ -2664,7 +2676,7 @@
                                                         ? &mLayerHierarchyBuilder.getHierarchy()
                                                         : nullptr,
                                                 updateAttachedChoreographer);
-        initiateDisplayModeChanges();
+        mustComposite |= initiateDisplayModeChanges();
     }
 
     updateCursorAsync();