SF: fix deadlock while switching resolution
Trying to grab mStateLock during kernelTimerChanged could lead to
deadlock when changing resolution as display gets recreated and the idle
timer may get stopped/re-started. The deadlock could happen when
calling OneShotTimer::stop() (due to thread join) in main thread while
kernelTimerChanged is waiting for lock.
Bug: 222755257
Test: cmd display set-user-preferred-display-mode
Change-Id: I0ccc7bccdcee98722c1dced09032ab3953d851cb
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index e8034de..350d709 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -6063,7 +6063,6 @@
static bool updateOverlay =
property_get_bool("debug.sf.kernel_idle_timer_update_overlay", true);
if (!updateOverlay) return;
- if (Mutex::Autolock lock(mStateLock); !isRefreshRateOverlayEnabled()) return;
// Update the overlay on the main thread to avoid race conditions with
// mRefreshRateConfigs->getCurrentRefreshRate()
@@ -6073,6 +6072,7 @@
ALOGW("%s: default display is null", __func__);
return;
}
+ if (!display->isRefreshRateOverlayEnabled()) return;
const auto desiredActiveMode = display->getDesiredActiveMode();
const std::optional<DisplayModeId> desiredModeId = desiredActiveMode