commit adc914ccd7dd60754843e1f33c956c0f51430036
author Ady Abraham <adyabr@google.com> Wed Oct 13 17:04:27 2021 -0700
committer Ady Abraham <adyabr@google.com> Wed Oct 13 17:10:16 2021 -0700
tree 319441452a35df084ac5e57c28fb66563f52cb84
parent 4f960d169f0dfbfaba43b0e1033843fcf55fd8a2

SF: acquire/release screen for active display only

SurfaceFlinger assumes that there is at most a single internal display
powered on at a given time, and mark it as the active display. However,
in order to be robust against rare race conditions where displays might
be on together for a short period of time, we add a check to make sure
that we tell the scheduler that the screen was acquired/released only
for the active display.

Bug: 201605862
Test: SF unit tests
Change-Id: I25b3f807d9f5d93ae88ac8a6026cee76cb69f493

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 39d4d2a..29d35c2 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4611,7 +4611,7 @@
             ALOGW("Couldn't set SCHED_FIFO on display on: %s\n", strerror(errno));
         }
         getHwComposer().setPowerMode(displayId, mode);
-        if (display->isInternal() && mode != hal::PowerMode::DOZE_SUSPEND) {
+        if (isDisplayActiveLocked(display) && mode != hal::PowerMode::DOZE_SUSPEND) {
             setHWCVsyncEnabled(displayId, mHWCVsyncPendingState);
             mScheduler->onScreenAcquired(mAppConnectionHandle);
             mScheduler->resyncToHardwareVsync(true, vsyncPeriod);
@@ -4628,7 +4628,7 @@
         if (SurfaceFlinger::setSchedAttr(false) != NO_ERROR) {
             ALOGW("Couldn't set uclamp.min on display off: %s\n", strerror(errno));
         }
-        if (display->isInternal() && currentMode != hal::PowerMode::DOZE_SUSPEND) {
+        if (isDisplayActiveLocked(display) && currentMode != hal::PowerMode::DOZE_SUSPEND) {
             mScheduler->disableHardwareVsync(true);
             mScheduler->onScreenReleased(mAppConnectionHandle);
         }
@@ -4642,13 +4642,13 @@
     } else if (mode == hal::PowerMode::DOZE || mode == hal::PowerMode::ON) {
         // Update display while dozing
         getHwComposer().setPowerMode(displayId, mode);
-        if (display->isInternal() && currentMode == hal::PowerMode::DOZE_SUSPEND) {
+        if (isDisplayActiveLocked(display) && currentMode == hal::PowerMode::DOZE_SUSPEND) {
             mScheduler->onScreenAcquired(mAppConnectionHandle);
             mScheduler->resyncToHardwareVsync(true, vsyncPeriod);
         }
     } else if (mode == hal::PowerMode::DOZE_SUSPEND) {
         // Leave display going to doze
-        if (display->isInternal()) {
+        if (isDisplayActiveLocked(display)) {
             mScheduler->disableHardwareVsync(true);
             mScheduler->onScreenReleased(mAppConnectionHandle);
         }
@@ -4658,7 +4658,7 @@
         getHwComposer().setPowerMode(displayId, mode);
     }
 
-    if (display->isInternal()) {
+    if (isDisplayActiveLocked(display)) {
         mTimeStats->setPowerMode(mode);
         mRefreshRateStats->setPowerMode(mode);
         mScheduler->setDisplayPowerState(mode == hal::PowerMode::ON);