commit 0fd773f8b8b8224b3ca40afb1e1c42d0786519ea
author Vishnu Nair <vishnun@google.com> Mon Aug 05 21:16:15 2024 +0000
committer Vishnu Nair <vishnun@google.com> Mon Aug 05 16:50:21 2024 -0700
tree e157910d44eb6e89d404e5fdd5deabe727168709
parent 057e57726ea60c55660589ac8c01f285f712b03d

Fix framerate propagation from child to parent layers

We were not resetting the framerate vote of the parent layer
after the child frame rate vote was removed. Fix this and
add tests to verify this behavior does not regress.

Flag: EXEMPT (removing old flags)
Bug: 330785038
Test: presubmit
Change-Id: I88d60484d4dfdfa4b09c98484867a49545f60257

services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp

diff --git a/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp b/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
index 47fd700..c874db3 100644
--- a/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
+++ b/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
@@ -561,6 +561,7 @@
         updateSnapshot(*snapshot, args, *layer, parentSnapshot, traversalPath);
     }
 
+    bool childHasValidFrameRate = false;
     for (auto& [childHierarchy, variant] : hierarchy.mChildren) {
         LayerHierarchy::ScopedAddToTraversalPath addChildToPath(traversalPath,
                                                                 childHierarchy->getLayer()->id,
@@ -568,7 +569,8 @@
         const LayerSnapshot& childSnapshot =
                 updateSnapshotsInHierarchy(args, *childHierarchy, traversalPath, *snapshot,
                                            depth + 1);
-        updateFrameRateFromChildSnapshot(*snapshot, childSnapshot, args);
+        updateFrameRateFromChildSnapshot(*snapshot, childSnapshot, *childHierarchy->getLayer(),
+                                         args, &childHasValidFrameRate);
     }
 
     return *snapshot;
@@ -675,9 +677,10 @@
     }
 }
 
-void LayerSnapshotBuilder::updateFrameRateFromChildSnapshot(LayerSnapshot& snapshot,
-                                                            const LayerSnapshot& childSnapshot,
-                                                            const Args& args) {
+void LayerSnapshotBuilder::updateFrameRateFromChildSnapshot(
+        LayerSnapshot& snapshot, const LayerSnapshot& childSnapshot,
+        const RequestedLayerState& /* requestedChildState */, const Args& args,
+        bool* outChildHasValidFrameRate) {
     if (args.forceUpdate == ForceUpdateFlags::NONE &&
         !args.layerLifecycleManager.getGlobalChanges().any(
                 RequestedLayerState::Changes::Hierarchy) &&
@@ -687,7 +690,7 @@
     }
 
     using FrameRateCompatibility = scheduler::FrameRateCompatibility;
-    if (snapshot.frameRate.isValid()) {
+    if (snapshot.inheritedFrameRate.isValid() || *outChildHasValidFrameRate) {
         // we already have a valid framerate.
         return;
     }
@@ -704,13 +707,18 @@
     const auto layerVotedWithExactCompatibility = childSnapshot.frameRate.vote.rate.isValid() &&
             childSnapshot.frameRate.vote.type == FrameRateCompatibility::Exact;
 
-    bool childHasValidFrameRate = layerVotedWithDefaultCompatibility || layerVotedWithNoVote ||
+    *outChildHasValidFrameRate |= layerVotedWithDefaultCompatibility || layerVotedWithNoVote ||
             layerVotedWithCategory || layerVotedWithExactCompatibility;
 
     // If we don't have a valid frame rate, but the children do, we set this
     // layer as NoVote to allow the children to control the refresh rate
-    if (childHasValidFrameRate) {
-        snapshot.frameRate = scheduler::LayerInfo::FrameRate(Fps(), FrameRateCompatibility::NoVote);
+    static const auto noVote =
+            scheduler::LayerInfo::FrameRate(Fps(), FrameRateCompatibility::NoVote);
+    if (*outChildHasValidFrameRate) {
+        snapshot.frameRate = noVote;
+        snapshot.changes |= RequestedLayerState::Changes::FrameRate;
+    } else if (snapshot.frameRate != snapshot.inheritedFrameRate) {
+        snapshot.frameRate = snapshot.inheritedFrameRate;
         snapshot.changes |= RequestedLayerState::Changes::FrameRate;
     }
 }