Merge "improve h/w composer documentation" into ics-mr1
diff --git a/include/hardware/hwcomposer.h b/include/hardware/hwcomposer.h
index a17f3e4..b4a7a7a 100644
--- a/include/hardware/hwcomposer.h
+++ b/include/hardware/hwcomposer.h
@@ -287,6 +287,11 @@
* entire composition has been handled by SurfaceFlinger with OpenGL ES.
* In this case, (*set)() behaves just like eglSwapBuffers().
*
+ * dpy, sur, and list are set to NULL to indicate that the screen is
+ * turning off. This happens WITHOUT prepare() being called first.
+ * This is a good time to free h/w resources and/or power
+ * the relevant h/w blocks down.
+ *
* IMPORTANT NOTE: there is an implicit layer containing opaque black
* pixels behind all the layers in the list.
* It is the responsibility of the hwcomposer module to make
