Commit 7d90ba5f authored Aug 08, 2019 by Lloyd Pique

SF: Present before signalling presentation done

In doing the refactor, I had effectively swapped the calls to
HWComposer::presentAndGetReleaseFences() and
DisplaySurface::onFrameCommitted() so that onFrameCommitted was being
called before the display was presented.

If client composition was used for those frames, the result was that the
GPU composed buffer on display could be written to (cleared) before it was
actually replaced by a new buffer.

Bug: 138914274
Test: Unable to reproduce black scanlines in Hangouts on Walleye
Change-Id: I13625f124130826a5f80337b74e937f1291220e1

parent 16d9c4bf

services/surfaceflinger/CompositionEngine/src/Output.cpp

+2 −2

Original line number	Diff line number	Diff line
		@@ -300,10 +300,10 @@ void Output::postFramebuffer() {
		return;
		}

		mRenderSurface->onPresentDisplayCompleted();

		auto frame = presentAndGetFrameFences();

		mRenderSurface->onPresentDisplayCompleted();

		for (auto& layer : getOutputLayersOrderedByZ()) {
		// The layer buffer from the previous frame (if any) is released
		// by HWC only when the release fence from this frame (if any) is