diff --git a/include/gui/ISurfaceTexture.h b/include/gui/ISurfaceTexture.h
index 99aa1ad..e705c6f 100644
--- a/include/gui/ISurfaceTexture.h
+++ b/include/gui/ISurfaceTexture.h
@@ -41,7 +41,10 @@
 protected:
     friend class SurfaceTextureClient;
 
-    enum { BUFFER_NEEDS_REALLOCATION = 1 };
+    enum {
+        BUFFER_NEEDS_REALLOCATION = 0x1,
+        RELEASE_ALL_BUFFERS       = 0x2,
+    };
 
     // requestBuffer requests a new buffer for the given index. The server (i.e.
     // the ISurfaceTexture implementation) assigns the newly created buffer to
@@ -94,6 +97,13 @@
     // query retrieves some information for this surface
     // 'what' tokens allowed are that of android_natives.h
     virtual int query(int what, int* value) = 0;
+
+    // setSynchronousMode set whether dequeueBuffer is synchronous or
+    // asynchronous. In synchronous mode, dequeueBuffer blocks until
+    // a buffer is available, the currently bound buffer can be dequeued and
+    // queued buffers will be retired in order.
+    // The default mode is asynchronous.
+    virtual status_t setSynchronousMode(bool enabled) = 0;
 };
 
 // ----------------------------------------------------------------------------
diff --git a/include/gui/SurfaceTexture.h b/include/gui/SurfaceTexture.h
index 5a371de..271a35f 100644
--- a/include/gui/SurfaceTexture.h
+++ b/include/gui/SurfaceTexture.h
@@ -38,7 +38,10 @@
 class SurfaceTexture : public BnSurfaceTexture {
 public:
     enum { MIN_UNDEQUEUED_BUFFERS = 2 };
-    enum { MIN_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS + 1 };
+    enum {
+        MIN_ASYNC_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS + 1,
+        MIN_SYNC_BUFFER_SLOTS  = MIN_UNDEQUEUED_BUFFERS
+    };
     enum { NUM_BUFFER_SLOTS = 32 };
 
     struct FrameAvailableListener : public virtual RefBase {
@@ -78,6 +81,13 @@
 
     virtual int query(int what, int* value);
 
+    // setSynchronousMode set whether dequeueBuffer is synchronous or
+    // asynchronous. In synchronous mode, dequeueBuffer blocks until
+    // a buffer is available, the currently bound buffer can be dequeued and
+    // queued buffers will be retired in order.
+    // The default mode is asynchronous.
+    virtual status_t setSynchronousMode(bool enabled);
+
     // updateTexImage sets the image contents of the target texture to that of
     // the most recently queued buffer.
     //
@@ -85,6 +95,11 @@
     // target texture belongs is bound to the calling thread.
     status_t updateTexImage();
 
+    // setBufferCountServer set the buffer count. If the client has requested
+    // a buffer count using setBufferCount, the server-buffer count will
+    // take effect once the client sets the count back to zero.
+    status_t setBufferCountServer(int bufferCount);
+
     // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix
     // associated with the texture image set by the most recent call to
     // updateTexImage.
@@ -142,13 +157,6 @@
     // getCurrentTransform returns the transform of the current buffer
     uint32_t getCurrentTransform() const;
 
-    // setSynchronousMode set whether dequeueBuffer is synchronous or
-    // asynchronous. In synchronous mode, dequeueBuffer blocks until
-    // a buffer is available, the currently bound buffer can be dequeued and
-    // queued buffers will be retired in order.
-    // The default mode is asynchronous.
-    status_t setSynchronousMode(bool enabled);
-
 protected:
 
     // freeAllBuffers frees the resources (both GraphicBuffer and EGLImage) for
@@ -163,6 +171,8 @@
     EGLImageKHR createImage(EGLDisplay dpy,
             const sp<GraphicBuffer>& graphicBuffer);
 
+    status_t setBufferCountServerLocked(int bufferCount);
+
     enum { INVALID_BUFFER_SLOT = -1 };
 
     struct BufferSlot {
@@ -234,10 +244,18 @@
     uint32_t mPixelFormat;
 
     // mBufferCount is the number of buffer slots that the client and server
-    // must maintain. It defaults to MIN_BUFFER_SLOTS and can be changed by
-    // calling setBufferCount.
+    // must maintain. It defaults to MIN_ASYNC_BUFFER_SLOTS and can be changed
+    // by calling setBufferCount or setBufferCountServer
     int mBufferCount;
 
+    // mRequestedBufferCount is the number of buffer slots requested by the
+    // client. The default is zero, which means the client doesn't care how
+    // many buffers there is.
+    int mClientBufferCount;
+
+    // mServerBufferCount buffer count requested by the server-side
+    int mServerBufferCount;
+
     // mCurrentTexture is the buffer slot index of the buffer that is currently
     // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT,
     // indicating that no buffer slot is currently bound to the texture. Note,
diff --git a/include/gui/SurfaceTextureClient.h b/include/gui/SurfaceTextureClient.h
index c77bc4c..e7c6e24 100644
--- a/include/gui/SurfaceTextureClient.h
+++ b/include/gui/SurfaceTextureClient.h
@@ -84,7 +84,6 @@
     int getConnectedApi() const;
 
     enum { MIN_UNDEQUEUED_BUFFERS = SurfaceTexture::MIN_UNDEQUEUED_BUFFERS };
-    enum { MIN_BUFFER_SLOTS = SurfaceTexture::MIN_BUFFER_SLOTS };
     enum { NUM_BUFFER_SLOTS = SurfaceTexture::NUM_BUFFER_SLOTS };
     enum { DEFAULT_FORMAT = PIXEL_FORMAT_RGBA_8888 };