From 0fe32ae50bcbf6d2a281bdc407ce56f3d05632c5 Mon Sep 17 00:00:00 2001
From: Ruchi Kandoi <kandoiruchi@google.com>
Date: Fri, 11 Jul 2014 10:55:05 -0700
Subject: [PATCH] PowerManager: Adds a call to reduce refresh rate while device
 is in BatterySaverMode.

Adds a binder call to the surface flinger to change the refresh rate
while the device is in BatterySaverMode.

Change-Id: I9b5fdcc279757ceb4b9917cb0445643b50133a04
---
 .../server/power/PowerManagerService.java      | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/services/core/java/com/android/server/power/PowerManagerService.java b/services/core/java/com/android/server/power/PowerManagerService.java
index a69dd30bc0dc1..ebad4224199af 100644
--- a/services/core/java/com/android/server/power/PowerManagerService.java
+++ b/services/core/java/com/android/server/power/PowerManagerService.java
@@ -58,6 +58,8 @@ import android.os.SystemProperties;
 import android.os.SystemService;
 import android.os.UserHandle;
 import android.os.WorkSource;
+import android.os.Parcel;
+import android.os.ServiceManager;
 import android.provider.Settings;
 import android.service.dreams.DreamManagerInternal;
 import android.util.EventLog;
@@ -659,6 +661,7 @@ public final class PowerManagerService extends com.android.server.SystemService
         if (mLowPowerModeEnabled != lowPowerModeEnabled) {
             mLowPowerModeEnabled = lowPowerModeEnabled;
             powerHintInternal(POWER_HINT_LOW_POWER_MODE, lowPowerModeEnabled ? 1 : 0);
+            setSurfaceFlingerLowPowerMode(lowPowerModeEnabled ? 1 : 0);
             mLowPowerModeEnabled = lowPowerModeEnabled;
             BackgroundThread.getHandler().post(new Runnable() {
                 @Override
@@ -2094,6 +2097,21 @@ public final class PowerManagerService extends com.android.server.SystemService
         nativeSendPowerHint(hintId, data);
     }
 
+    private static void setSurfaceFlingerLowPowerMode(int enabled) {
+        try {
+            final IBinder flinger = ServiceManager.getService("SurfaceFlinger");
+            if (flinger != null) {
+                final Parcel data = Parcel.obtain();
+                data.writeInterfaceToken("android.ui.ISurfaceComposer");
+                data.writeInt(enabled);
+                flinger.transact(1016, data, null, 0);
+                data.recycle();
+            }
+        } catch (RemoteException ex) {
+            Slog.e(TAG, "Failed to reduce refresh rate", ex);
+        }
+    }
+
     /**
      * Low-level function turn the device off immediately, without trying
      * to be clean.  Most people should use {@link ShutdownThread} for a clean shutdown.