Throttle proximity sensor values so we do not process more than one change a second.
This is to prevent a noisy proximity sensor from causing the screen to turn on and off
in rapid succession, which can trigger race conditions in the keyguard manager.
Change-Id: I2c6e54e4b41716e038854ed9a827c901579c8865
Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/services/java/com/android/server/PowerManagerService.java b/services/java/com/android/server/PowerManagerService.java
index 93b469f..a03ac6c 100644
--- a/services/java/com/android/server/PowerManagerService.java
+++ b/services/java/com/android/server/PowerManagerService.java
@@ -93,6 +93,9 @@
// How long to wait to debounce light sensor changes.
private static final int LIGHT_SENSOR_DELAY = 1000;
+ // For debouncing the proximity sensor.
+ private static final int PROXIMITY_SENSOR_DELAY = 1000;
+
// trigger proximity if distance is less than 5 cm
private static final float PROXIMITY_THRESHOLD = 5.0f;
@@ -162,6 +165,8 @@
private boolean mKeyboardVisible = false;
private boolean mUserActivityAllowed = true;
private boolean mProximitySensorActive = false;
+ private int mProximityPendingValue = -1; // -1 == nothing, 0 == inactive, 1 == active
+ private long mLastProximityEventTime;
private int mTotalDelaySetting;
private int mKeylightDelay;
private int mDimDelay;
@@ -886,6 +891,8 @@
pw.println(" mStayOnWhilePluggedInPartialLock=" + mStayOnWhilePluggedInPartialLock);
pw.println(" mPreventScreenOnPartialLock=" + mPreventScreenOnPartialLock);
pw.println(" mProximitySensorActive=" + mProximitySensorActive);
+ pw.println(" mProximityPendingValue=" + mProximityPendingValue);
+ pw.println(" mLastProximityEventTime=" + mLastProximityEventTime);
pw.println(" mLightSensorEnabled=" + mLightSensorEnabled);
pw.println(" mLightSensorValue=" + mLightSensorValue);
pw.println(" mLightSensorPendingValue=" + mLightSensorPendingValue);
@@ -1895,6 +1902,17 @@
}
}
+ private Runnable mProximityTask = new Runnable() {
+ public void run() {
+ synchronized (mLocks) {
+ if (mProximityPendingValue != -1) {
+ proximityChangedLocked(mProximityPendingValue == 1);
+ mProximityPendingValue = -1;
+ }
+ }
+ }
+ };
+
private Runnable mAutoBrightnessTask = new Runnable() {
public void run() {
synchronized (mLocks) {
@@ -2327,6 +2345,7 @@
long identity = Binder.clearCallingIdentity();
try {
mSensorManager.unregisterListener(mProximityListener);
+ mHandler.removeCallbacks(mProximityTask);
} finally {
Binder.restoreCallingIdentity(identity);
}
@@ -2338,6 +2357,22 @@
}
}
+ private void proximityChangedLocked(boolean active) {
+ if (mSpew) {
+ Log.d(TAG, "proximityChangedLocked, active: " + active);
+ }
+ if (active) {
+ goToSleepLocked(SystemClock.uptimeMillis());
+ mProximitySensorActive = true;
+ } else {
+ // proximity sensor negative events trigger as user activity.
+ // temporarily set mUserActivityAllowed to true so this will work
+ // even when the keyguard is on.
+ mProximitySensorActive = false;
+ forceUserActivityLocked();
+ }
+ }
+
private void enableLightSensor(boolean enable) {
if (mDebugLightSensor) {
Log.d(TAG, "enableLightSensor " + enable);
@@ -2365,23 +2400,22 @@
long milliseconds = event.timestamp / 1000000;
synchronized (mLocks) {
float distance = event.values[0];
+ long timeSinceLastEvent = milliseconds - mLastProximityEventTime;
+ mLastProximityEventTime = milliseconds;
+ mHandler.removeCallbacks(mProximityTask);
+
// compare against getMaximumRange to support sensors that only return 0 or 1
- if (distance >= 0.0 && distance < PROXIMITY_THRESHOLD &&
- distance < mProximitySensor.getMaximumRange()) {
- if (mSpew) {
- Log.d(TAG, "onSensorChanged: proximity active, distance: " + distance);
- }
- goToSleepLocked(milliseconds);
- mProximitySensorActive = true;
+ boolean active = (distance >= 0.0 && distance < PROXIMITY_THRESHOLD &&
+ distance < mProximitySensor.getMaximumRange());
+
+ if (timeSinceLastEvent < PROXIMITY_SENSOR_DELAY) {
+ // enforce delaying atleast PROXIMITY_SENSOR_DELAY before processing
+ mProximityPendingValue = (active ? 1 : 0);
+ mHandler.postDelayed(mProximityTask, PROXIMITY_SENSOR_DELAY - timeSinceLastEvent);
} else {
- // proximity sensor negative events trigger as user activity.
- // temporarily set mUserActivityAllowed to true so this will work
- // even when the keyguard is on.
- if (mSpew) {
- Log.d(TAG, "onSensorChanged: proximity inactive, distance: " + distance);
- }
- mProximitySensorActive = false;
- forceUserActivityLocked();
+ // process the value immediately
+ mProximityPendingValue = -1;
+ proximityChangedLocked(active);
}
}
}
