commit 89f5d4ebf7ba08e4f655550623fb5d78aa638f28
author Alec Mouri <alecmouri@google.com> Fri Oct 20 17:12:49 2023 +0000
committer Alec Mouri <alecmouri@google.com> Wed Nov 01 21:29:59 2023 +0000
tree f9925efd3198efd8d8cfccdfd67f3ef28c35bc7a
parent 14bebe0a3e3f9af775253d7b769641dae9b5b165

Front buffered layers vote for max

...because all known use-cases for beam racing want low latency which
implies clocking the display to max

Bug: 305997105
Test: libsurfaceflinger_unittest
Test: test app with front buffered layers + youtube pip stays at max
Change-Id: Ibe33d4b43ea4943874f104409e3bc247f00cae33

services/surfaceflinger/Scheduler/LayerHistory.cpp

diff --git a/services/surfaceflinger/Scheduler/LayerHistory.cpp b/services/surfaceflinger/Scheduler/LayerHistory.cpp
index 21bbb08..8fc9cba 100644
--- a/services/surfaceflinger/Scheduler/LayerHistory.cpp
+++ b/services/surfaceflinger/Scheduler/LayerHistory.cpp
@@ -51,6 +51,11 @@
         return true;
     }
 
+    // Make all front buffered layers active
+    if (FlagManager::getInstance().vrr_config() && info.isFrontBuffered() && info.isVisible()) {
+        return true;
+    }
+
     return info.isVisible() && info.getLastUpdatedTime() >= threshold;
 }
 

services/surfaceflinger/Scheduler/LayerInfo.cpp

diff --git a/services/surfaceflinger/Scheduler/LayerInfo.cpp b/services/surfaceflinger/Scheduler/LayerInfo.cpp
index 54e9022..8d18769 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.cpp
+++ b/services/surfaceflinger/Scheduler/LayerInfo.cpp
@@ -334,6 +334,14 @@
         return votes;
     }
 
+    // Vote for max refresh rate whenever we're front-buffered.
+    if (FlagManager::getInstance().vrr_config() && isFrontBuffered()) {
+        ATRACE_FORMAT_INSTANT("front buffered");
+        ALOGV("%s is front-buffered", mName.c_str());
+        votes.push_back({LayerHistory::LayerVoteType::Max, Fps()});
+        return votes;
+    }
+
     const LayerInfo::Frequent frequent = isFrequent(now);
     mIsFrequencyConclusive = frequent.isConclusive;
     if (!frequent.isFrequent) {
@@ -394,6 +402,10 @@
     return mLayerProps->frameRateSelectionPriority;
 }
 
+bool LayerInfo::isFrontBuffered() const {
+    return mLayerProps->isFrontBuffered;
+}
+
 FloatRect LayerInfo::getBounds() const {
     return mLayerProps->bounds;
 }

services/surfaceflinger/Scheduler/LayerInfo.h

diff --git a/services/surfaceflinger/Scheduler/LayerInfo.h b/services/surfaceflinger/Scheduler/LayerInfo.h
index 7d3cffa..03ab0df 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.h
+++ b/services/surfaceflinger/Scheduler/LayerInfo.h
@@ -200,6 +200,7 @@
     FrameRate getSetFrameRateVote() const;
     bool isVisible() const;
     int32_t getFrameRateSelectionPriority() const;
+    bool isFrontBuffered() const;
     FloatRect getBounds() const;
     ui::Transform getTransform() const;
 
@@ -360,6 +361,7 @@
     LayerInfo::FrameRate setFrameRateVote;
     int32_t frameRateSelectionPriority = -1;
     bool isSmallDirty = false;
+    bool isFrontBuffered = false;
 };
 
 } // namespace scheduler