Merge "SF: Prefer external displays as pacesetters given equal refresh rates" into main (aa5f85e8) · Commits · e / os / android_frameworks_native

services/surfaceflinger/Scheduler/Scheduler.cpp

+29 −8

Original line number	Diff line number	Diff line
		@@ -162,6 +162,7 @@ PhysicalDisplayId Scheduler::selectPacesetterDisplayLocked(
		// The first display should be the new pacesetter if none of the displays are powered on.
		const auto& [firstDisplayId, firstDisplay] = *mDisplays.begin();
		PhysicalDisplayId newPacesetterId = firstDisplayId;
		ui::DisplayConnectionType newPacesetterConnectionType = firstDisplay.connectionType;
		// Only assigning the actual refresh rate if the first display is powered on ensures that any
		// other powered-on display will take over the new pacesetter designation regardless of its
		// refresh rate.
		@@ -179,24 +180,44 @@ PhysicalDisplayId Scheduler::selectPacesetterDisplayLocked(
		const Fps displayVsyncRate = display.selectorPtr->getActiveMode().modePtr->getVsyncRate();
		if (isStrictlyLess(newPacesetterVsyncRate, displayVsyncRate)) {
		newPacesetterId = id;
		newPacesetterConnectionType = display.connectionType;
		newPacesetterVsyncRate = displayVsyncRate;
		}
		}

		// The slack in the difference between refresh rate difference to consider them roughly equal
		// for pacesetter selection purposes. E.g. 59.98 and 60.02Hz Should be considered roughly equal.
		const auto isVsyncRateApproxEqual = [&](const Display& display, Fps otherFps) -> bool {
		constexpr float kRefreshRateEpsilon = 0.1f;
		const Fps displayVsyncRate = display.selectorPtr->getActiveMode().modePtr->getVsyncRate();
		return std::abs(displayVsyncRate.getValue() - otherFps.getValue()) < kRefreshRateEpsilon;
		};

		// If the current pacesetter display is powered on and its refresh rate is not too far off from
		// the newly selected pacesetter display, prefer to keep the current one to avoid churn.
		if (const auto pacesetterOpt = pacesetterDisplayLocked()) {
		const auto& pacesetter = pacesetterOpt->get();
		if (pacesetter.powerMode == hal::PowerMode::ON) {
		const Fps currentPacesetterVsyncRate =
		if (isVsyncRateApproxEqual(pacesetter, newPacesetterVsyncRate)) {
		newPacesetterId = pacesetter.displayId;
		newPacesetterConnectionType = pacesetter.connectionType;
		newPacesetterVsyncRate =
		pacesetter.selectorPtr->getActiveMode().modePtr->getVsyncRate();
		const float rateDiff =
		newPacesetterVsyncRate.getValue() - currentPacesetterVsyncRate.getValue();
		constexpr float kRefreshRateEpsilon = 0.1f;
		}
		}
		}

		if (rateDiff < kRefreshRateEpsilon) {
		newPacesetterId = pacesetter.displayId;
		newPacesetterVsyncRate = currentPacesetterVsyncRate;
		// Prefer external displays as pacesetter, as it is more likely the external display will be the
		// user's main display.
		if (newPacesetterConnectionType != ui::DisplayConnectionType::External) {
		for (const auto& [id, display] : mDisplays) {
		if (display.powerMode != hal::PowerMode::ON \|\|
		display.connectionType != ui::DisplayConnectionType::External) {
		continue;
		}

		if (isVsyncRateApproxEqual(display, newPacesetterVsyncRate)) {
		return id;
		}
		}
		}

services/surfaceflinger/tests/unittests/SchedulerTest.cpp

+20 −0

Original line number	Diff line number	Diff line
		@@ -1539,6 +1539,26 @@ TEST_F(SelectPacesetterDisplayTest, TwoDisplaysWithinEpsilon) FTL_FAKE_GUARD(kMa
		EXPECT_EQ(mScheduler->pacesetterDisplayId(), kDisplayId1);
		}

		TEST_F(SelectPacesetterDisplayTest, SameRefreshRateOneInternalOneExternal)
		FTL_FAKE_GUARD(kMainThreadContext) {
		SET_FLAG_FOR_TEST(flags::pacesetter_selection, true);

		constexpr PhysicalDisplayId kActiveDisplayId = kDisplayId1;
		mScheduler->registerDisplay(kDisplayId1, ui::DisplayConnectionType::Internal,
		std::make_shared<RefreshRateSelector>(kDisplay1Modes,
		kDisplay1Mode60->getId()),
		kActiveDisplayId);
		mScheduler->setDisplayPowerMode(kDisplayId1, hal::PowerMode::ON);

		auto selector2 =
		std::make_shared<RefreshRateSelector>(kDisplay2Modes, kDisplay2Mode60->getId());
		mScheduler->registerDisplay(kDisplayId2, ui::DisplayConnectionType::External, selector2,
		kActiveDisplayId);
		mScheduler->setDisplayPowerMode(kDisplayId2, hal::PowerMode::ON);

		EXPECT_EQ(mScheduler->pacesetterDisplayId(), kDisplayId2);
		}

		TEST_F(SchedulerTest, selectorPtrForLayerStack) FTL_FAKE_GUARD(kMainThreadContext) {
		SET_FLAG_FOR_TEST(flags::follower_arbitrary_refresh_rate_selection, true);