commit 0a3c4d6f8c95a89875455e989278a440822968d7
author Dan Stoza <stoza@google.com> Tue Apr 19 11:56:20 2016 -0700
committer Dan Stoza <stoza@google.com> Tue Apr 19 11:56:20 2016 -0700
tree d5d9a2bb282f90cb5632b74de8d8ee20c76c45d2
parent 6328134d8f3969e5cf345bec84b2c6455afc6a34

DispSync: Don't resync if HW vsync is unavailable

Don't attempt to resync to hardware vsync if it's not available (if
the display is blanked), which should prevent unusual sequences of
commands (enable vsync, then unblank) to hardware composer.

Bug: 28177844
Change-Id: I9d6046fb0a346830e98829fd250642f0809d7e31

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index c09920c..a69b11b 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -800,7 +800,8 @@
     if (makeAvailable) {
         mHWVsyncAvailable = true;
     } else if (!mHWVsyncAvailable) {
-        ALOGE("resyncToHardwareVsync called when HW vsync unavailable");
+        // Hardware vsync is not currently available, so abort the resync
+        // attempt for now
         return;
     }
 
@@ -834,7 +835,7 @@
 void SurfaceFlinger::resyncWithRateLimit() {
     static constexpr nsecs_t kIgnoreDelay = ms2ns(500);
     if (systemTime() - mLastSwapTime > kIgnoreDelay) {
-        resyncToHardwareVsync(true);
+        resyncToHardwareVsync(false);
     }
 }