surfaceflinger: fix fencing when composition mode switches
When a layer switches from HWC composition to GLES composition, we
use the GLES rendering fence to indicate that the previous layer
buffer is released by HWC. This is incorrect.
Bug: 68490054
Test: manual
Change-Id: I4070940c26d39251161f45682398e6987f4fba15
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index d29d9c1..32f3e18 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1924,13 +1924,22 @@
displayDevice->onSwapBuffersCompleted();
displayDevice->makeCurrent(mEGLDisplay, mEGLContext);
for (auto& layer : displayDevice->getVisibleLayersSortedByZ()) {
- sp<Fence> releaseFence = Fence::NO_FENCE;
+ // The layer buffer from the previous frame (if any) is released
+ // by HWC only when the release fence from this frame (if any) is
+ // signaled. Always get the release fence from HWC first.
+ auto hwcLayer = layer->getHwcLayer(hwcId);
+ sp<Fence> releaseFence = mHwc->getLayerReleaseFence(hwcId, hwcLayer);
+
+ // If the layer was client composited in the previous frame, we
+ // need to merge with the previous client target acquire fence.
+ // Since we do not track that, always merge with the current
+ // client target acquire fence when it is available, even though
+ // this is suboptimal.
if (layer->getCompositionType(hwcId) == HWC2::Composition::Client) {
- releaseFence = displayDevice->getClientTargetAcquireFence();
- } else {
- auto hwcLayer = layer->getHwcLayer(hwcId);
- releaseFence = mHwc->getLayerReleaseFence(hwcId, hwcLayer);
+ releaseFence = Fence::merge("LayerRelease", releaseFence,
+ displayDevice->getClientTargetAcquireFence());
}
+
layer->onLayerDisplayed(releaseFence);
}
if (hwcId >= 0) {