From 9f818ea463af7083fed619a7159c93905169503e Mon Sep 17 00:00:00 2001
From: Michael Wright <michaelwr@google.com>
Date: Fri, 29 Jul 2016 19:59:39 +0100
Subject: [PATCH] Prevent brightness changes before boot complete.

Bug: 29837667
Change-Id: I6385236786f6a73c64a61e1a5181c3787b68ed36
---
 .../java/com/android/server/power/PowerManagerService.java | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/power/PowerManagerService.java b/services/core/java/com/android/server/power/PowerManagerService.java
index 2215cbb904809..2824e6e66ffaf 100644
--- a/services/core/java/com/android/server/power/PowerManagerService.java
+++ b/services/core/java/com/android/server/power/PowerManagerService.java
@@ -2085,7 +2085,12 @@ public final class PowerManagerService extends SystemService
             float screenAutoBrightnessAdjustment = 0.0f;
             boolean autoBrightness = (mScreenBrightnessModeSetting ==
                     Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
-            if (isValidBrightness(mScreenBrightnessOverrideFromWindowManager)) {
+            if (!mBootCompleted) {
+                // Keep the brightness steady during boot. This requires the
+                // bootloader brightness and the default brightness to be identical.
+                autoBrightness = false;
+                brightnessSetByUser = false;
+            } else if (isValidBrightness(mScreenBrightnessOverrideFromWindowManager)) {
                 screenBrightness = mScreenBrightnessOverrideFromWindowManager;
                 autoBrightness = false;
                 brightnessSetByUser = false;