surfaceflinger: recompute visibility after sideband stream change

We normally recompute layer visibility when a layer gets its first
buffer; before then it's treated as invisible. Sideband layers never
get a buffer (as far as SurfaceFlinger knows), so never became
visible. Now we also recompute visibility when a layer gets a new
sideband stream.

Bug: 17752511
Change-Id: I84e150f196eb2eb7bcd2616248e5e3fa73624809

1 files changed, 4 insertions, 0 deletions

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index a36ddd9581..fa07656e23 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1042,6 +1042,10 @@ Region Layer::latchBuffer(bool& recomputeVisibleRegions)
     if (android_atomic_acquire_cas(true, false, &mSidebandStreamChanged) == 0) {
         // mSidebandStreamChanged was true
         mSidebandStream = mSurfaceFlingerConsumer->getSidebandStream();
+        recomputeVisibleRegions = true;
+
+        const State& s(getDrawingState());
+        return s.transform.transform(Region(Rect(s.active.w, s.active.h)));
     }
 
     Region outDirtyRegion;