Improve screen brightness boost behavior.

Wake-up when entering brightness boost mode, don't boost in ambient
mode since some display device drivers do strange things in that mode and
boost doesn't work.  Waking up feels more natural as well.

Don't flutter the power HAL's interactive mode bit simply due to changes
in display ready state since that may result in visible artifacts
such as display flashes.

Don't stop the auto-brightness sensor while temporarily boosted.

Don't prevent the display from entering the ready state while in brightness
boost since that would unnecessarily delay the transition from DOZING to AWAKE
until boost is finished.

Restart the user activity timeout when brightness boost ends and prevent
the display from dimming while boosted.

The pixel fairies basked in the sunlight.

Bug: 18262044
Bug: 18261782
Change-Id: I8c42a1e6091b0fe1253e90265ac248087ebc24e1
diff --git a/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java b/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
index ddefb1f..627d1d5 100644
--- a/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
+++ b/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
@@ -995,6 +995,10 @@
                 }
                 break;
             case MULTI_PRESS_POWER_BRIGHTNESS_BOOST:
+                Slog.i(TAG, "Starting brightness boost.");
+                if (!interactive) {
+                    wakeUpFromPowerKey(eventTime);
+                }
                 mPowerManager.boostScreenBrightness(eventTime);
                 break;
         }
diff --git a/services/core/java/com/android/server/display/DisplayPowerController.java b/services/core/java/com/android/server/display/DisplayPowerController.java
index 1d8003b..11fe545 100644
--- a/services/core/java/com/android/server/display/DisplayPowerController.java
+++ b/services/core/java/com/android/server/display/DisplayPowerController.java
@@ -570,11 +570,8 @@
         state = mPowerState.getScreenState();
 
         // Use zero brightness when screen is off.
-        // Use full brightness when screen brightness is boosted.
         if (state == Display.STATE_OFF) {
             brightness = PowerManager.BRIGHTNESS_OFF;
-        } else if (mPowerRequest.boostScreenBrightness) {
-            brightness = PowerManager.BRIGHTNESS_ON;
         }
 
         // Use default brightness when dozing unless overridden.
@@ -592,6 +589,16 @@
                     mPowerRequest.screenAutoBrightnessAdjustment);
         }
 
+        // Apply brightness boost.
+        // We do this here after configuring auto-brightness so that we don't
+        // disable the light sensor during this temporary state.  That way when
+        // boost ends we will be able to resume normal auto-brightness behavior
+        // without any delay.
+        if (mPowerRequest.boostScreenBrightness
+                && brightness != PowerManager.BRIGHTNESS_OFF) {
+            brightness = PowerManager.BRIGHTNESS_ON;
+        }
+
         // Apply auto-brightness.
         boolean slowChange = false;
         if (brightness < 0) {
diff --git a/services/core/java/com/android/server/power/PowerManagerService.java b/services/core/java/com/android/server/power/PowerManagerService.java
index 8682f5c..4d9f1a0 100644
--- a/services/core/java/com/android/server/power/PowerManagerService.java
+++ b/services/core/java/com/android/server/power/PowerManagerService.java
@@ -1234,6 +1234,7 @@
             // Phase 0: Basic state updates.
             updateIsPoweredLocked(mDirty);
             updateStayOnLocked(mDirty);
+            updateScreenBrightnessBoostLocked(mDirty);
 
             // Phase 1: Update wakefulness.
             // Loop because the wake lock and user activity computations are influenced
@@ -1465,7 +1466,8 @@
     private void updateUserActivitySummaryLocked(long now, int dirty) {
         // Update the status of the user activity timeout timer.
         if ((dirty & (DIRTY_WAKE_LOCKS | DIRTY_USER_ACTIVITY
-                | DIRTY_WAKEFULNESS | DIRTY_SETTINGS)) != 0) {
+                | DIRTY_WAKEFULNESS | DIRTY_SETTINGS
+                | DIRTY_SCREEN_BRIGHTNESS_BOOST)) != 0) {
             mHandler.removeMessages(MSG_USER_ACTIVITY_TIMEOUT);
 
             long nextTimeout = 0;
@@ -1641,7 +1643,8 @@
                 || mProximityPositive
                 || (mWakeLockSummary & WAKE_LOCK_STAY_AWAKE) != 0
                 || (mUserActivitySummary & (USER_ACTIVITY_SCREEN_BRIGHT
-                        | USER_ACTIVITY_SCREEN_DIM)) != 0;
+                        | USER_ACTIVITY_SCREEN_DIM)) != 0
+                || mScreenBrightnessBoostInProgress;
     }
 
     /**
@@ -1828,9 +1831,6 @@
                 | DIRTY_SETTINGS | DIRTY_SCREEN_BRIGHTNESS_BOOST)) != 0) {
             mDisplayPowerRequest.policy = getDesiredScreenPolicyLocked();
 
-            // Handle screen brightness boost timeout.
-            updateScreenBrightnessBoostLocked();
-
             // Determine appropriate screen brightness and auto-brightness adjustments.
             int screenBrightness = mScreenBrightnessSettingDefault;
             float screenAutoBrightnessAdjustment = 0.0f;
@@ -1879,7 +1879,7 @@
             }
 
             mDisplayReady = mDisplayManagerInternal.requestPowerState(mDisplayPowerRequest,
-                    mRequestWaitForNegativeProximity) && !mScreenBrightnessBoostInProgress;
+                    mRequestWaitForNegativeProximity);
             mRequestWaitForNegativeProximity = false;
 
             if (DEBUG_SPEW) {
@@ -1896,20 +1896,25 @@
         return mDisplayReady && !oldDisplayReady;
     }
 
-    private void updateScreenBrightnessBoostLocked() {
-        if (mScreenBrightnessBoostInProgress) {
-            mHandler.removeMessages(MSG_SCREEN_BRIGHTNESS_BOOST_TIMEOUT);
-            if (mLastScreenBrightnessBoostTime > mLastSleepTime) {
-                final long boostTimeout = mLastScreenBrightnessBoostTime +
-                        SCREEN_BRIGHTNESS_BOOST_TIMEOUT;
-                if (boostTimeout > SystemClock.uptimeMillis()) {
-                    Message msg = mHandler.obtainMessage(MSG_SCREEN_BRIGHTNESS_BOOST_TIMEOUT);
-                    msg.setAsynchronous(true);
-                    mHandler.sendMessageAtTime(msg, boostTimeout);
-                    return;
+    private void updateScreenBrightnessBoostLocked(int dirty) {
+        if ((dirty & DIRTY_SCREEN_BRIGHTNESS_BOOST) != 0) {
+            if (mScreenBrightnessBoostInProgress) {
+                final long now = SystemClock.uptimeMillis();
+                mHandler.removeMessages(MSG_SCREEN_BRIGHTNESS_BOOST_TIMEOUT);
+                if (mLastScreenBrightnessBoostTime > mLastSleepTime) {
+                    final long boostTimeout = mLastScreenBrightnessBoostTime +
+                            SCREEN_BRIGHTNESS_BOOST_TIMEOUT;
+                    if (boostTimeout > now) {
+                        Message msg = mHandler.obtainMessage(MSG_SCREEN_BRIGHTNESS_BOOST_TIMEOUT);
+                        msg.setAsynchronous(true);
+                        mHandler.sendMessageAtTime(msg, boostTimeout);
+                        return;
+                    }
                 }
+                mScreenBrightnessBoostInProgress = false;
+                userActivityNoUpdateLocked(now,
+                        PowerManager.USER_ACTIVITY_EVENT_OTHER, 0, Process.SYSTEM_UID);
             }
-            mScreenBrightnessBoostInProgress = false;
         }
     }
 
@@ -1940,7 +1945,8 @@
 
         if ((mWakeLockSummary & WAKE_LOCK_SCREEN_BRIGHT) != 0
                 || (mUserActivitySummary & USER_ACTIVITY_SCREEN_BRIGHT) != 0
-                || !mBootCompleted) {
+                || !mBootCompleted
+                || mScreenBrightnessBoostInProgress) {
             return DisplayPowerRequest.POLICY_BRIGHT;
         }
 
@@ -2037,15 +2043,13 @@
         final boolean needWakeLockSuspendBlocker = ((mWakeLockSummary & WAKE_LOCK_CPU) != 0);
         final boolean needDisplaySuspendBlocker = needDisplaySuspendBlockerLocked();
         final boolean autoSuspend = !needDisplaySuspendBlocker;
+        final boolean interactive = mDisplayPowerRequest.isBrightOrDim();
 
         // Disable auto-suspend if needed.
-        if (!autoSuspend) {
-            if (mDecoupleHalAutoSuspendModeFromDisplayConfig) {
-                setHalAutoSuspendModeLocked(false);
-            }
-            if (mDecoupleHalInteractiveModeFromDisplayConfig) {
-                setHalInteractiveModeLocked(true);
-            }
+        // FIXME We should consider just leaving auto-suspend enabled forever since
+        // we already hold the necessary wakelocks.
+        if (!autoSuspend && mDecoupleHalAutoSuspendModeFromDisplayConfig) {
+            setHalAutoSuspendModeLocked(false);
         }
 
         // First acquire suspend blockers if needed.
@@ -2058,6 +2062,22 @@
             mHoldingDisplaySuspendBlocker = true;
         }
 
+        // Inform the power HAL about interactive mode.
+        // Although we could set interactive strictly based on the wakefulness
+        // as reported by isInteractive(), it is actually more desirable to track
+        // the display policy state instead so that the interactive state observed
+        // by the HAL more accurately tracks transitions between AWAKE and DOZING.
+        // Refer to getDesiredScreenPolicyLocked() for details.
+        if (mDecoupleHalInteractiveModeFromDisplayConfig) {
+            // When becoming non-interactive, we want to defer sending this signal
+            // until the display is actually ready so that all transitions have
+            // completed.  This is probably a good sign that things have gotten
+            // too tangled over here...
+            if (interactive || mDisplayReady) {
+                setHalInteractiveModeLocked(interactive);
+            }
+        }
+
         // Then release suspend blockers if needed.
         if (!needWakeLockSuspendBlocker && mHoldingWakeLockSuspendBlocker) {
             mWakeLockSuspendBlocker.release();
@@ -2069,13 +2089,8 @@
         }
 
         // Enable auto-suspend if needed.
-        if (autoSuspend) {
-            if (mDecoupleHalInteractiveModeFromDisplayConfig) {
-                setHalInteractiveModeLocked(false);
-            }
-            if (mDecoupleHalAutoSuspendModeFromDisplayConfig) {
-                setHalAutoSuspendModeLocked(true);
-            }
+        if (autoSuspend && mDecoupleHalAutoSuspendModeFromDisplayConfig) {
+            setHalAutoSuspendModeLocked(true);
         }
     }
 
@@ -2097,6 +2112,9 @@
                 return true;
             }
         }
+        if (mScreenBrightnessBoostInProgress) {
+            return true;
+        }
         // Let the system suspend if the screen is off or dozing.
         return false;
     }