diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index e2852a7..9da96c4 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -141,6 +141,7 @@
 
     uint32_t                getLayerStack() const { return mLayerStack; }
     int32_t                 getDisplayType() const { return mType; }
+    bool                    isPrimary() const { return mType == DISPLAY_PRIMARY; }
     int32_t                 getHwcDisplayId() const { return mHwcDisplayId; }
     const wp<IBinder>&      getDisplayToken() const { return mDisplayToken; }