Only update the display when brightness and state are valid.
If either are invalid then we're in an indeterminant state and need to
wait until that's resolved. This should only happens at boot and then is
immediately corrected when we set our initial desired state. By not
checking the validity of the to-be-applied state, we're actually turning
the display to our assumed state briefly (i.e. OFF) even though we don't
know what state we actually want yet.
Fixes: 196566901
Fixes: 196274559
Fixes: 195071558
Test: Reboot device, no flicker in boot animation
Change-Id: Ie5a4c186e3af31eb8810f5c7014a4e2cc7cdbf91
(cherry picked from commit a00cda677956e0553a6de4df8f25ebc9b2b3039e)
diff --git a/services/core/java/com/android/server/display/DisplayPowerState.java b/services/core/java/com/android/server/display/DisplayPowerState.java
index 6af1923..147050c 100644
--- a/services/core/java/com/android/server/display/DisplayPowerState.java
+++ b/services/core/java/com/android/server/display/DisplayPowerState.java
@@ -411,7 +411,7 @@
* Updates the state of the screen and backlight asynchronously on a separate thread.
*/
private final class PhotonicModulator extends Thread {
- private static final int INITIAL_SCREEN_STATE = Display.STATE_OFF; // unknown, assume off
+ private static final int INITIAL_SCREEN_STATE = Display.STATE_UNKNOWN;
private static final float INITIAL_BACKLIGHT_FLOAT = PowerManager.BRIGHTNESS_INVALID_FLOAT;
private final Object mLock = new Object();
@@ -494,7 +494,9 @@
if (!backlightChanged) {
mBacklightChangeInProgress = false;
}
- if (!stateChanged && !backlightChanged) {
+ boolean valid = state != Display.STATE_UNKNOWN && !Float.isNaN(brightnessState);
+ boolean changed = stateChanged || backlightChanged;
+ if (!valid || !changed) {
try {
mLock.wait();
} catch (InterruptedException ex) {
