SystemUI: Disable HW acceleration for status bar

This change switches the status bar rendering to use CPU rendering to an
RGB_565 window.

Change-Id: I45c03989efc9cc9ea71ff169fafedf048de9d612

1 files changed, 9 insertions, 4 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/StatusBar.java b/packages/SystemUI/src/com/android/systemui/statusbar/StatusBar.java
index 2e1803e..2be35b7 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/StatusBar.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/StatusBar.java
@@ -118,15 +118,20 @@ public abstract class StatusBar extends SystemUI implements CommandQueue.Callbac
                 WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                     | WindowManager.LayoutParams.FLAG_TOUCHABLE_WHEN_WAKING
                     | WindowManager.LayoutParams.FLAG_SPLIT_TOUCH,
-                PixelFormat.OPAQUE);
+                // We use a pixel format of RGB565 for the status bar to save memory bandwidth and
+                // to ensure that the layer can be handled by HWComposer.  On some devices the
+                // HWComposer is unable to handle SW-rendered RGBX_8888 layers.
+                PixelFormat.RGB_565);
         
         // the status bar should be in an overlay if possible
         final Display defaultDisplay 
             = ((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE))
                 .getDefaultDisplay();
-        if (ActivityManager.isHighEndGfx(defaultDisplay)) {
-            lp.flags |= WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED;
-        }
+
+        // We explicitly leave FLAG_HARDWARE_ACCELERATED out of the flags.  The status bar occupies
+        // very little screen real-estate and is updated fairly frequently.  By using CPU rendering
+        // for the status bar, we prevent the GPU from having to wake up just to do these small
+        // updates, which should help keep power consumption down.
 
         lp.gravity = getStatusBarGravity();
         lp.setTitle("StatusBar");