commit a3ba7fa4665a1df144ba777a37dbb979bab0d390
author Leon Scroggins III <scroggo@google.com> Wed May 22 16:34:52 2024 -0400
committer Leon Scroggins III <scroggo@google.com> Thu May 30 13:17:18 2024 -0400
tree dfd7e839f964c1c1c8522268ecf3752f9db15a22
parent 229c5228fbe7bf6343c36a4d64ddffce73b421c2

Output::presentFrameAndReleaseLayers: flush pending commands for OFF displays

Most work from this method can be skipped if the display is not enabled.
However, uncaching buffers should still occur. If the display is
disabled and there are buffers to uncache, still flush pending commands.
They should only contain commands that are meaningful for a disabled
display, like bufferSlotsToClear.

Bug: 330806421
Test: libcompositionengine_test
Flag: flush_buffer_slots_to_uncache
Change-Id: I7baa3e76af86329fb266395e63e92a0ba38967f4

services/surfaceflinger/CompositionEngine/src/Output.cpp

diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index 84f3f25..5b9a102 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -479,8 +479,9 @@
     devOptRepaintFlash(refreshArgs);
     finishFrame(std::move(result));
     ftl::Future<std::monostate> future;
+    const bool flushEvenWhenDisabled = !refreshArgs.bufferIdsToUncache.empty();
     if (mOffloadPresent) {
-        future = presentFrameAndReleaseLayersAsync();
+        future = presentFrameAndReleaseLayersAsync(flushEvenWhenDisabled);
 
         // Only offload for this frame. The next frame will determine whether it
         // needs to be offloaded. Leave the HwcAsyncWorker in place. For one thing,
@@ -488,7 +489,7 @@
         // we don't want to churn.
         mOffloadPresent = false;
     } else {
-        presentFrameAndReleaseLayers();
+        presentFrameAndReleaseLayers(flushEvenWhenDisabled);
         future = ftl::yield<std::monostate>({});
     }
     renderCachedSets(refreshArgs);
@@ -1100,9 +1101,9 @@
     finishPrepareFrame();
 }
 
-ftl::Future<std::monostate> Output::presentFrameAndReleaseLayersAsync() {
+ftl::Future<std::monostate> Output::presentFrameAndReleaseLayersAsync(bool flushEvenWhenDisabled) {
     return ftl::Future<bool>(std::move(mHwComposerAsyncWorker->send([&]() {
-               presentFrameAndReleaseLayers();
+               presentFrameAndReleaseLayers(flushEvenWhenDisabled);
                return true;
            })))
             .then([](bool) { return std::monostate{}; });
@@ -1177,7 +1178,8 @@
         }
     }
 
-    presentFrameAndReleaseLayers();
+    constexpr bool kFlushEvenWhenDisabled = false;
+    presentFrameAndReleaseLayers(kFlushEvenWhenDisabled);
 
     std::this_thread::sleep_for(*refreshArgs.devOptFlashDirtyRegionsDelay);
 
@@ -1567,11 +1569,16 @@
     return false;
 }
 
-void Output::presentFrameAndReleaseLayers() {
+void Output::presentFrameAndReleaseLayers(bool flushEvenWhenDisabled) {
     ATRACE_FORMAT("%s for %s", __func__, mNamePlusId.c_str());
     ALOGV(__FUNCTION__);
 
     if (!getState().isEnabled) {
+        if (flushEvenWhenDisabled && FlagManager::getInstance().flush_buffer_slots_to_uncache()) {
+            // Some commands, like clearing buffer slots, should still be executed
+            // even if the display is not enabled.
+            executeCommands();
+        }
         return;
     }