Merge "Move toggling of kernel idle timer to SF" into rvc-dev

5 files changed, 109 insertions, 5 deletions

diff --git a/services/surfaceflinger/Scheduler/RefreshRateConfigs.cpp b/services/surfaceflinger/Scheduler/RefreshRateConfigs.cpp
index 6dbff14244..a6036c6b37 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateConfigs.cpp
+++ b/services/surfaceflinger/Scheduler/RefreshRateConfigs.cpp
@@ -595,4 +595,28 @@ float RefreshRateConfigs::findClosestKnownFrameRate(float frameRate) const {
     return distance1 < distance2 ? *lowerBound : *std::prev(lowerBound);
 }
 
+RefreshRateConfigs::KernelIdleTimerAction RefreshRateConfigs::getIdleTimerAction() const {
+    std::lock_guard lock(mLock);
+    const auto& deviceMin = getMinRefreshRate();
+    const auto& minByPolicy = getMinRefreshRateByPolicyLocked();
+    const auto& maxByPolicy = getMaxRefreshRateByPolicyLocked();
+
+    // Kernel idle timer will set the refresh rate to the device min. If DisplayManager says that
+    // the min allowed refresh rate is higher than the device min, we do not want to enable the
+    // timer.
+    if (deviceMin < minByPolicy) {
+        return RefreshRateConfigs::KernelIdleTimerAction::TurnOff;
+    }
+    if (minByPolicy == maxByPolicy) {
+        // Do not sent the call to toggle off kernel idle timer if the device min and policy min and
+        // max are all the same. This saves us extra unnecessary calls to sysprop.
+        if (deviceMin == minByPolicy) {
+            return RefreshRateConfigs::KernelIdleTimerAction::NoChange;
+        }
+        return RefreshRateConfigs::KernelIdleTimerAction::TurnOff;
+    }
+    // Turn on the timer in all other cases.
+    return RefreshRateConfigs::KernelIdleTimerAction::TurnOn;
+}
+
 } // namespace android::scheduler
diff --git a/services/surfaceflinger/Scheduler/RefreshRateConfigs.h b/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
index 584a5e7c72..8a51b85207 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
+++ b/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
@@ -82,6 +82,8 @@ public:
             return configId != other.configId || hwcConfig != other.hwcConfig;
         }
 
+        bool operator<(const RefreshRate& other) const { return getFps() < other.getFps(); }
+
         bool operator==(const RefreshRate& other) const { return !(*this != other); }
 
     private:
@@ -271,6 +273,17 @@ public:
     RefreshRateConfigs(const std::vector<std::shared_ptr<const HWC2::Display::Config>>& configs,
                        HwcConfigIndexType currentConfigId);
 
+    // Class to enumerate options around toggling the kernel timer on and off. We have an option
+    // for no change to avoid extra calls to kernel.
+    enum class KernelIdleTimerAction {
+        NoChange, // Do not change the idle timer.
+        TurnOff,  // Turn off the idle timer.
+        TurnOn    // Turn on the idle timer.
+    };
+    // Checks whether kernel idle timer should be active depending the policy decisions around
+    // refresh rates.
+    KernelIdleTimerAction getIdleTimerAction() const;
+
 private:
     friend class RefreshRateConfigsTest;
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index ef315e24c6..2e019039f8 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -23,6 +23,7 @@
 
 #include "SurfaceFlinger.h"
 
+#include <android-base/properties.h>
 #include <android/configuration.h>
 #include <android/hardware/configstore/1.0/ISurfaceFlingerConfigs.h>
 #include <android/hardware/configstore/1.1/ISurfaceFlingerConfigs.h>
@@ -444,6 +445,9 @@ SurfaceFlinger::SurfaceFlinger(Factory& factory) : SurfaceFlinger(factory, SkipI
     }
 
     useFrameRateApi = use_frame_rate_api(true);
+
+    mKernelIdleTimerEnabled = mSupportKernelIdleTimer = sysprop::support_kernel_idle_timer(false);
+    base::SetProperty(KERNEL_IDLE_TIMER_PROP, mKernelIdleTimerEnabled ? "true" : "false");
 }
 
 SurfaceFlinger::~SurfaceFlinger() = default;
@@ -5355,8 +5359,7 @@ void SurfaceFlinger::kernelTimerChanged(bool expired) {
         const auto& min = mRefreshRateConfigs->getMinRefreshRate();
 
         if (current != min) {
-            const auto kernelTimerEnabled = property_get_bool(KERNEL_IDLE_TIMER_PROP, false);
-            const bool timerExpired = kernelTimerEnabled && expired;
+            const bool timerExpired = mKernelIdleTimerEnabled && expired;
 
             if (Mutex::Autolock lock(mStateLock); mRefreshRateOverlay) {
                 mRefreshRateOverlay->changeRefreshRate(timerExpired ? min : current);
@@ -5366,6 +5369,35 @@ void SurfaceFlinger::kernelTimerChanged(bool expired) {
     }));
 }
 
+void SurfaceFlinger::toggleKernelIdleTimer() {
+    using KernelIdleTimerAction = scheduler::RefreshRateConfigs::KernelIdleTimerAction;
+
+    // If the support for kernel idle timer is disabled in SF code, don't do anything.
+    if (!mSupportKernelIdleTimer) {
+        return;
+    }
+    const KernelIdleTimerAction action = mRefreshRateConfigs->getIdleTimerAction();
+
+    switch (action) {
+        case KernelIdleTimerAction::TurnOff:
+            if (mKernelIdleTimerEnabled) {
+                ATRACE_INT("KernelIdleTimer", 0);
+                base::SetProperty(KERNEL_IDLE_TIMER_PROP, "false");
+                mKernelIdleTimerEnabled = false;
+            }
+            break;
+        case KernelIdleTimerAction::TurnOn:
+            if (!mKernelIdleTimerEnabled) {
+                ATRACE_INT("KernelIdleTimer", 1);
+                base::SetProperty(KERNEL_IDLE_TIMER_PROP, "true");
+                mKernelIdleTimerEnabled = true;
+            }
+            break;
+        case KernelIdleTimerAction::NoChange:
+            break;
+    }
+}
+
 // A simple RAII class to disconnect from an ANativeWindow* when it goes out of scope
 class WindowDisconnector {
 public:
@@ -5992,14 +6024,14 @@ status_t SurfaceFlinger::setDesiredDisplayConfigSpecsInternal(
           currentPolicy.primaryRange.max, currentPolicy.appRequestRange.min,
           currentPolicy.appRequestRange.max);
 
-    // TODO(b/140204874): This hack triggers a notification that something has changed, so
-    // that listeners that care about a change in allowed configs can get the notification.
-    // Giving current ActiveConfig so that most other listeners would just drop the event
+    // TODO(b/140204874): Leave the event in until we do proper testing with all apps that might
+    // be depending in this callback.
     const nsecs_t vsyncPeriod =
             mRefreshRateConfigs->getRefreshRateFromConfigId(display->getActiveConfig())
                     .getVsyncPeriod();
     mScheduler->onPrimaryDisplayConfigChanged(mAppConnectionHandle, display->getId()->value,
                                               display->getActiveConfig(), vsyncPeriod);
+    toggleKernelIdleTimer();
 
     auto configId = mScheduler->getPreferredConfigId();
     auto& preferredRefreshRate = configId
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 38db62be1d..ccaeb2d858 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -535,6 +535,13 @@ private:
     void repaintEverythingForHWC() override;
     // Called when kernel idle timer has expired. Used to update the refresh rate overlay.
     void kernelTimerChanged(bool expired) override;
+    // Toggles the kernel idle timer on or off depending the policy decisions around refresh rates.
+    void toggleKernelIdleTimer();
+    // Keeps track of whether the kernel idle timer is currently enabled, so we don't have to
+    // make calls to sys prop each time.
+    bool mKernelIdleTimerEnabled = false;
+    // Keeps track of whether the kernel timer is supported on the SF side.
+    bool mSupportKernelIdleTimer = false;
     /* ------------------------------------------------------------------------
      * Message handling
      */
diff --git a/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp b/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
index f24575e351..fed591cb19 100644
--- a/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
+++ b/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
@@ -1420,6 +1420,34 @@ TEST_F(RefreshRateConfigsTest, getBestRefreshRate_KnownFrameRate) {
     }
 }
 
+TEST_F(RefreshRateConfigsTest, testComparisonOperator) {
+    EXPECT_TRUE(mExpected60Config < mExpected90Config);
+    EXPECT_FALSE(mExpected60Config < mExpected60Config);
+    EXPECT_FALSE(mExpected90Config < mExpected90Config);
+}
+
+TEST_F(RefreshRateConfigsTest, testKernelIdleTimerAction) {
+    using KernelIdleTimerAction = scheduler::RefreshRateConfigs::KernelIdleTimerAction;
+
+    auto refreshRateConfigs =
+            std::make_unique<RefreshRateConfigs>(m60_90Device,
+                                                 /*currentConfigId=*/HWC_CONFIG_ID_90);
+    // SetPolicy(60, 90), current 90Hz => TurnOn.
+    EXPECT_EQ(KernelIdleTimerAction::TurnOn, refreshRateConfigs->getIdleTimerAction());
+
+    // SetPolicy(60, 90), current 60Hz => TurnOn.
+    ASSERT_GE(refreshRateConfigs->setDisplayManagerPolicy({HWC_CONFIG_ID_60, {60, 90}}), 0);
+    EXPECT_EQ(KernelIdleTimerAction::TurnOn, refreshRateConfigs->getIdleTimerAction());
+
+    // SetPolicy(60, 60), current 60Hz => NoChange, avoid extra calls.
+    ASSERT_GE(refreshRateConfigs->setDisplayManagerPolicy({HWC_CONFIG_ID_60, {60, 60}}), 0);
+    EXPECT_EQ(KernelIdleTimerAction::NoChange, refreshRateConfigs->getIdleTimerAction());
+
+    // SetPolicy(90, 90), current 90Hz => TurnOff.
+    ASSERT_GE(refreshRateConfigs->setDisplayManagerPolicy({HWC_CONFIG_ID_90, {90, 90}}), 0);
+    EXPECT_EQ(KernelIdleTimerAction::TurnOff, refreshRateConfigs->getIdleTimerAction());
+}
+
 } // namespace
 } // namespace scheduler
 } // namespace android