Android side of the fix for [2121211] Sholes has stutter during animations

a new method, compostionComplete() is added to the framebuffer hal, it is used by surfaceflinger to signal the driver that the composition is complete, BEFORE it releases its client. This gives a chance to the driver to

include/ui/FramebufferNativeWindow.h

@@ -54,6 +54,7 @@ public:
 
     bool isUpdateOnDemand() const { return mUpdateOnDemand; }
     status_t setUpdateRectangle(const Rect& updateRect);
+    status_t compositionComplete();
     
 private:
     friend class LightRefBase<FramebufferNativeWindow>;    

libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp

@@ -297,9 +297,9 @@ uint32_t DisplayHardware::getPageFlipCount() const {
     return mPageFlipCount;
 }
 
-/*
- * "Flip" the front and back buffers.
- */
+status_t DisplayHardware::compositionComplete() const {
+    return mNativeWindow->compositionComplete();
+}
 
 void DisplayHardware::flip(const Region& dirty) const
 {

libs/surfaceflinger/DisplayHardware/DisplayHardware.h

@@ -80,6 +80,8 @@ public:
     EGLDisplay getEGLDisplay() const { return mDisplay; }
     overlay_control_device_t* getOverlayEngine() const { return mOverlayEngine; }
     
+    status_t compositionComplete() const;
+    
     Rect bounds() const {
         return Rect(mWidth, mHeight);
     }

libs/surfaceflinger/SurfaceFlinger.cpp

@@ -495,6 +495,9 @@ bool SurfaceFlinger::threadLoop()
         // repaint the framebuffer (if needed)
         handleRepaint();
 
+        // inform the h/w that we're done compositing
+        hw.compositionComplete();
+
         // release the clients before we flip ('cause flip might block)
         unlockClients();
 

libs/ui/FramebufferNativeWindow.cpp

@@ -158,6 +158,14 @@ status_t FramebufferNativeWindow::setUpdateRectangle(const Rect& r)
     return fbDev->setUpdateRect(fbDev, r.left, r.top, r.width(), r.height());
 }
 
+status_t FramebufferNativeWindow::compositionComplete()
+{
+    if (fbDev->compositionComplete) {
+        return fbDev->compositionComplete(fbDev);
+    }
+    return INVALID_OPERATION;
+}
+
 int FramebufferNativeWindow::setSwapInterval(
         android_native_window_t* window, int interval) 
 {