From 3a3cad30c40c8eb87671262a9fe7f0e214b6a934 Mon Sep 17 00:00:00 2001 From: Mathias Agopian Date: Tue, 18 Oct 2011 17:36:28 -0700 Subject: [PATCH] Don't call hwc set() if there is nothing new to do there was situations where SF's main loop would run (as if there was an invalidate), but the dirty region was empty (so no new buffers were retired). In this case we return early and don't swap, which would cause drawing artifacts. Bug: 5476838 Change-Id: Id3b7bf4b7aabec7919c50d9278eb2165973a4c3d --- services/surfaceflinger/SurfaceFlinger.cpp | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp index 3c48b7e27..595ec1e12 100644 --- a/services/surfaceflinger/SurfaceFlinger.cpp +++ b/services/surfaceflinger/SurfaceFlinger.cpp @@ -445,6 +445,11 @@ bool SurfaceFlinger::threadLoop() // post surfaces (if needed) handlePageFlip(); + if (mDirtyRegion.isEmpty()) { + // nothing new to do. + return true; + } + if (UNLIKELY(mHwWorkListDirty)) { // build the h/w work list handleWorkList(); @@ -478,6 +483,9 @@ bool SurfaceFlinger::threadLoop() void SurfaceFlinger::postFramebuffer() { + // this should never happen. we do the flip anyways so we don't + // risk to cause a deadlock with hwc + LOGW_IF(mSwapRegion.isEmpty(), "mSwapRegion is empty"); const DisplayHardware& hw(graphicPlane(0).displayHardware()); const nsecs_t now = systemTime(); mDebugInSwapBuffers = now; @@ -938,7 +946,7 @@ void SurfaceFlinger::setupHardwareComposer(Region& dirtyInOut) // data. // // Also we want to make sure to not clear areas that belong to - // layers above that won't redraw (we would just erasing them), + // layers above that won't redraw (we would just be erasing them), // that is, we can't erase anything outside the dirty region. Region transparent; @@ -1769,7 +1777,7 @@ status_t SurfaceFlinger::onTransact( void SurfaceFlinger::repaintEverything() { Mutex::Autolock _l(mStateLock); const DisplayHardware& hw(graphicPlane(0).displayHardware()); - mDirtyRegion.set(hw.bounds()); // careful that's not thread-safe + mDirtyRegion.set(hw.bounds()); signalEvent(); }