diff --git a/libs/surfaceflinger_client/SharedBufferStack.cpp b/libs/surfaceflinger_client/SharedBufferStack.cpp
index 5c4f920..881ffd4 100644
--- a/libs/surfaceflinger_client/SharedBufferStack.cpp
+++ b/libs/surfaceflinger_client/SharedBufferStack.cpp
@@ -67,6 +67,18 @@
     identity = i;
 }
 
+status_t SharedBufferStack::setCrop(int buffer, const Rect& crop)
+{
+    if (uint32_t(buffer) >= NUM_BUFFER_MAX)
+        return BAD_INDEX;
+
+    buffers[buffer].crop.l = uint16_t(crop.left);
+    buffers[buffer].crop.t = uint16_t(crop.top);
+    buffers[buffer].crop.r = uint16_t(crop.right);
+    buffers[buffer].crop.b = uint16_t(crop.bottom);
+    return NO_ERROR;
+}
+
 status_t SharedBufferStack::setDirtyRegion(int buffer, const Region& dirty)
 {
     if (uint32_t(buffer) >= NUM_BUFFER_MAX)
@@ -75,21 +87,21 @@
     // in the current implementation we only send a single rectangle
     size_t count;
     Rect const* r = dirty.getArray(&count);
-    FlatRegion& reg(dirtyRegion[buffer]);
+    FlatRegion& reg(buffers[buffer].dirtyRegion);
     if (count > FlatRegion::NUM_RECT_MAX) {
         const Rect bounds(dirty.getBounds());
         reg.count = 1;
-        reg.rects[0] = uint16_t(bounds.left);
-        reg.rects[1] = uint16_t(bounds.top);
-        reg.rects[2] = uint16_t(bounds.right);
-        reg.rects[3] = uint16_t(bounds.bottom);
+        reg.rects[0].l = uint16_t(bounds.left);
+        reg.rects[0].t = uint16_t(bounds.top);
+        reg.rects[0].r = uint16_t(bounds.right);
+        reg.rects[0].b = uint16_t(bounds.bottom);
     } else {
         reg.count = count;
         for (size_t i=0 ; i<count ; i++) {
-            reg.rects[i*4 + 0] = uint16_t(r[i].left);
-            reg.rects[i*4 + 1] = uint16_t(r[i].top);
-            reg.rects[i*4 + 2] = uint16_t(r[i].right);
-            reg.rects[i*4 + 3] = uint16_t(r[i].bottom);
+            reg.rects[i].l = uint16_t(r[i].left);
+            reg.rects[i].t = uint16_t(r[i].top);
+            reg.rects[i].r = uint16_t(r[i].right);
+            reg.rects[i].b = uint16_t(r[i].bottom);
         }
     }
     return NO_ERROR;
@@ -101,19 +113,24 @@
     if (uint32_t(buffer) >= NUM_BUFFER_MAX)
         return res;
 
-    const FlatRegion& reg(dirtyRegion[buffer]);
+    const FlatRegion& reg(buffers[buffer].dirtyRegion);
     if (reg.count > FlatRegion::NUM_RECT_MAX)
         return res;
 
     if (reg.count == 1) {
-        res.set(Rect(reg.rects[0], reg.rects[1], reg.rects[2], reg.rects[3]));
+        const Rect r(
+                reg.rects[0].l,
+                reg.rects[0].t,
+                reg.rects[0].r,
+                reg.rects[0].b);
+        res.set(r);
     } else {
         for (size_t i=0 ; i<reg.count ; i++) {
             const Rect r(
-                    reg.rects[i*4 + 0],
-                    reg.rects[i*4 + 1],
-                    reg.rects[i*4 + 2],
-                    reg.rects[i*4 + 3]);
+                    reg.rects[i].l,
+                    reg.rects[i].t,
+                    reg.rects[i].r,
+                    reg.rects[i].b);
             res.orSelf(r);
         }
     }
@@ -372,6 +389,12 @@
     return (android_atomic_and(~mask, &stack.reallocMask) & mask) != 0;
 }
 
+status_t SharedBufferClient::setCrop(int buffer, const Rect& crop)
+{
+    SharedBufferStack& stack( *mSharedStack );
+    return stack.setCrop(buffer, crop);
+}
+
 status_t SharedBufferClient::setDirtyRegion(int buffer, const Region& reg)
 {
     SharedBufferStack& stack( *mSharedStack );
@@ -389,7 +412,7 @@
     mSharedStack->available = num;
     mSharedStack->queued = 0;
     mSharedStack->reallocMask = 0;
-    memset(mSharedStack->dirtyRegion, 0, sizeof(mSharedStack->dirtyRegion));
+    memset(mSharedStack->buffers, 0, sizeof(mSharedStack->buffers));
 }
 
 ssize_t SharedBufferServer::retireAndLock()
diff --git a/libs/surfaceflinger_client/Surface.cpp b/libs/surfaceflinger_client/Surface.cpp
index 3c7a4d2..39938e8 100644
--- a/libs/surfaceflinger_client/Surface.cpp
+++ b/libs/surfaceflinger_client/Surface.cpp
@@ -552,6 +552,7 @@
     }
     
     int32_t bufIdx = GraphicBuffer::getSelf(buffer)->getIndex();
+    mSharedBufferClient->setCrop(bufIdx, mNextBufferCrop);
     mSharedBufferClient->setDirtyRegion(bufIdx, mDirtyRegion);
     err = mSharedBufferClient->queue(bufIdx);
     LOGE_IF(err, "error queuing buffer %d (%s)", bufIdx, strerror(-err));
@@ -581,6 +582,10 @@
 
 int Surface::perform(int operation, va_list args)
 {
+    status_t err = validate();
+    if (err != NO_ERROR)
+        return err;
+
     int res = NO_ERROR;
     switch (operation) {
     case NATIVE_WINDOW_SET_USAGE:
@@ -592,6 +597,9 @@
     case NATIVE_WINDOW_DISCONNECT:
         res = dispatch_disconnect( args );
         break;
+    case NATIVE_WINDOW_SET_CROP:
+        res = dispatch_crop( args );
+        break;
     default:
         res = NAME_NOT_FOUND;
         break;
@@ -611,6 +619,10 @@
     int api = va_arg(args, int);
     return disconnect( api );
 }
+int Surface::dispatch_crop(va_list args) {
+    android_native_rect_t const* rect = va_arg(args, android_native_rect_t*);
+    return crop( reinterpret_cast<Rect const*>(rect) );
+}
 
 
 void Surface::setUsage(uint32_t reqUsage)
@@ -669,6 +681,14 @@
     return mConnected;
 }
 
+int Surface::crop(Rect const* rect)
+{
+    Mutex::Autolock _l(mSurfaceLock);
+    // TODO: validate rect size
+    mNextBufferCrop = *rect;
+    return NO_ERROR;
+}
+
 
 // ----------------------------------------------------------------------------