commit 69b9e62fd59d084e6b50a9afd6e8074a8c59594c
author Ady Abraham <adyabr@google.com> Mon Jul 19 12:24:31 2021 -0700
committer Ady Abraham <adyabr@google.com> Mon Jul 19 16:28:52 2021 -0700
tree 81fdd7fbdf22f9f8defd78dab147601eff68b40f
parent 6a409e17600f320134dea722247c15770030d7b2

SF: fix expected vsync time when changing work duration

When changing the work duration for a scheduled callback, we should
apply it on the next frame only if we would skip a callback call.
This change fixes the condition where we apply a different work
duration that doesn't change the wake up time but rather changes
the expected vsync time.

Test: TouchLatency bouncy ball + expand notification shade
Bug: 191969790
Change-Id: I067693fe361200a6f899bd81b74d8a1a155a452d

services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp

diff --git a/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp b/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp
index 28be962..b805bf6 100644
--- a/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp
@@ -84,10 +84,13 @@
                                                       VSyncTracker& tracker, nsecs_t now) {
     auto nextVsyncTime = tracker.nextAnticipatedVSyncTimeFrom(
             std::max(timing.earliestVsync, now + timing.workDuration + timing.readyDuration));
+    auto nextWakeupTime = nextVsyncTime - timing.workDuration - timing.readyDuration;
 
     bool const wouldSkipAVsyncTarget =
             mArmedInfo && (nextVsyncTime > (mArmedInfo->mActualVsyncTime + mMinVsyncDistance));
-    if (wouldSkipAVsyncTarget) {
+    bool const wouldSkipAWakeup =
+            mArmedInfo && ((nextWakeupTime > (mArmedInfo->mActualWakeupTime + mMinVsyncDistance)));
+    if (wouldSkipAVsyncTarget && wouldSkipAWakeup) {
         return getExpectedCallbackTime(nextVsyncTime, timing);
     }
 
@@ -97,9 +100,9 @@
     if (alreadyDispatchedForVsync) {
         nextVsyncTime =
                 tracker.nextAnticipatedVSyncTimeFrom(*mLastDispatchTime + mMinVsyncDistance);
+        nextWakeupTime = nextVsyncTime - timing.workDuration - timing.readyDuration;
     }
 
-    auto const nextWakeupTime = nextVsyncTime - timing.workDuration - timing.readyDuration;
     auto const nextReadyTime = nextVsyncTime - timing.readyDuration;
     mScheduleTiming = timing;
     mArmedInfo = {nextWakeupTime, nextVsyncTime, nextReadyTime};