Merge "Fix DisplayManager race condition when state is unknown" into tm-qpr-dev (ee0c2b11) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/display/DisplayPowerController.java

+3 −3

Original line number	Diff line number	Diff line
		@@ -817,9 +817,9 @@ final class DisplayPowerController implements AutomaticBrightnessController.Call
		mDisplayDeviceConfig = config;
		loadFromDisplayDeviceConfig(token, info);

		// Since the underlying display-device changed, we really don't know the
		// last command that was sent to change it's state. Lets assume it is off and we
		// trigger a change immediately.
		/// Since the underlying display-device changed, we really don't know the
		// last command that was sent to change it's state. Lets assume it is unknown so
		// that we trigger a change immediately.
		mPowerState.resetScreenState();
		}
		if (mIsEnabled != isEnabled \|\| mIsInTransition != isInTransition) {

+5 −11

Original line number	Diff line number	Diff line
		@@ -340,20 +340,12 @@ final class DisplayPowerState {
		}

		/**
		* Resets the screen state to {@link Display#STATE_OFF}. Even though we do not know the last
		* state that was sent to the underlying display-device, we assume it is off.
		*
		* We do not set the screen state to {@link Display#STATE_UNKNOWN} to avoid getting in the state
		* where PhotonicModulator holds onto the lock. This happens because we currently try to keep
		* the mScreenState and mPendingState in sync, however if the screenState is set to
		* {@link Display#STATE_UNKNOWN} here, mPendingState will get progressed to this, which will
		* force the PhotonicModulator thread to wait onto the lock to take it out of that state.
		* b/262294651 for more info.
		* Resets the screen state to unknown. Useful when the underlying display-device changes for the
		* LogicalDisplay and we do not know the last state that was sent to it.
		*/
		void resetScreenState() {
		mScreenState = Display.STATE_OFF;
		mScreenState = Display.STATE_UNKNOWN;
		mScreenReady = false;
		scheduleScreenUpdate();
		}

		private void scheduleScreenUpdate() {
		@@ -514,6 +506,8 @@ final class DisplayPowerState {
		boolean valid = state != Display.STATE_UNKNOWN && !Float.isNaN(brightnessState);
		boolean changed = stateChanged \|\| backlightChanged;
		if (!valid \|\| !changed) {
		mStateChangeInProgress = false;
		mBacklightChangeInProgress = false;
		try {
		mLock.wait();
		} catch (InterruptedException ex) {