[SurfaceFlinger] Don't touch hw vsync in DEFAULT RR with kernel timeout

As a power optimization, hw vsync shouldn't be enabled when the kernel
timer resets if the display is going to run at 60hz anyways.

Bug: 136197211
Test: systrace when scrolling at peak refresh rate of 60hz.
Change-Id: Ic7df3e7b735f79b183cdd91f770de83082e491b4
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index cfdbd91..d2270d3 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -380,11 +380,17 @@
 }
 
 void Scheduler::setChangeRefreshRateCallback(
-        const ChangeRefreshRateCallback& changeRefreshRateCallback) {
+        const ChangeRefreshRateCallback&& changeRefreshRateCallback) {
     std::lock_guard<std::mutex> lock(mCallbackLock);
     mChangeRefreshRateCallback = changeRefreshRateCallback;
 }
 
+void Scheduler::setGetCurrentRefreshRateTypeCallback(
+        const GetCurrentRefreshRateTypeCallback&& getCurrentRefreshRateTypeCallback) {
+    std::lock_guard<std::mutex> lock(mCallbackLock);
+    mGetCurrentRefreshRateTypeCallback = getCurrentRefreshRateTypeCallback;
+}
+
 void Scheduler::setGetVsyncPeriodCallback(const GetVsyncPeriod&& getVsyncPeriod) {
     std::lock_guard<std::mutex> lock(mCallbackLock);
     mGetVsyncPeriod = getVsyncPeriod;
@@ -427,8 +433,13 @@
 void Scheduler::resetKernelTimerCallback() {
     ATRACE_INT("ExpiredKernelIdleTimer", 0);
     std::lock_guard<std::mutex> lock(mCallbackLock);
-    if (mGetVsyncPeriod) {
-        resyncToHardwareVsync(true, mGetVsyncPeriod());
+    if (mGetVsyncPeriod && mGetCurrentRefreshRateTypeCallback) {
+        // If we're not in performance mode then the kernel timer shouldn't do
+        // anything, as the refresh rate during DPU power collapse will be the
+        // same.
+        if (mGetCurrentRefreshRateTypeCallback() == Scheduler::RefreshRateType::PERFORMANCE) {
+            resyncToHardwareVsync(true, mGetVsyncPeriod());
+        }
     }
 }
 
@@ -450,10 +461,16 @@
 }
 
 void Scheduler::expiredKernelTimerCallback() {
+    std::lock_guard<std::mutex> lock(mCallbackLock);
     ATRACE_INT("ExpiredKernelIdleTimer", 1);
-    // Disable HW Vsync if the timer expired, as we don't need it
-    // enabled if we're not pushing frames.
-    disableHardwareVsync(false);
+    if (mGetCurrentRefreshRateTypeCallback) {
+        if (mGetCurrentRefreshRateTypeCallback() != Scheduler::RefreshRateType::PERFORMANCE) {
+            // Disable HW Vsync if the timer expired, as we don't need it
+            // enabled if we're not pushing frames, and if we're in PERFORMANCE
+            // mode then we'll need to re-update the DispSync model anyways.
+            disableHardwareVsync(false);
+        }
+    }
 }
 
 std::string Scheduler::doDump() {
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index eaad37c..c97664f 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -49,6 +49,7 @@
     }
 
     using RefreshRateType = scheduler::RefreshRateConfigs::RefreshRateType;
+    using GetCurrentRefreshRateTypeCallback = std::function<RefreshRateType()>;
     using ChangeRefreshRateCallback = std::function<void(RefreshRateType, ConfigEvent)>;
     using GetVsyncPeriod = std::function<nsecs_t()>;
 
@@ -165,7 +166,9 @@
     // Updates FPS based on the most content presented.
     void updateFpsBasedOnContent();
     // Callback that gets invoked when Scheduler wants to change the refresh rate.
-    void setChangeRefreshRateCallback(const ChangeRefreshRateCallback& changeRefreshRateCallback);
+    void setChangeRefreshRateCallback(const ChangeRefreshRateCallback&& changeRefreshRateCallback);
+    void setGetCurrentRefreshRateTypeCallback(
+            const GetCurrentRefreshRateTypeCallback&& getCurrentRefreshRateType);
     void setGetVsyncPeriodCallback(const GetVsyncPeriod&& getVsyncPeriod);
 
     // Returns whether idle timer is enabled or not
@@ -283,6 +286,7 @@
     std::unique_ptr<scheduler::IdleTimer> mTouchTimer;
 
     std::mutex mCallbackLock;
+    GetCurrentRefreshRateTypeCallback mGetCurrentRefreshRateTypeCallback GUARDED_BY(mCallbackLock);
     ChangeRefreshRateCallback mChangeRefreshRateCallback GUARDED_BY(mCallbackLock);
     GetVsyncPeriod mGetVsyncPeriod GUARDED_BY(mCallbackLock);
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 94eeef5..577deff 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -713,6 +713,24 @@
                 Mutex::Autolock lock(mStateLock);
                 setRefreshRateTo(type, event);
             });
+    mScheduler->setGetCurrentRefreshRateTypeCallback([this] {
+        Mutex::Autolock lock(mStateLock);
+        const auto display = getDefaultDisplayDeviceLocked();
+        if (!display) {
+            // If we don't have a default display the fallback to the default
+            // refresh rate type
+            return RefreshRateType::DEFAULT;
+        }
+
+        const int configId = display->getActiveConfig();
+        for (const auto& [type, refresh] : mRefreshRateConfigs.getRefreshRates()) {
+            if (refresh && refresh->configId == configId) {
+                return type;
+            }
+        }
+        // This should never happen, but just gracefully fallback to default.
+        return RefreshRateType::DEFAULT;
+    });
     mScheduler->setGetVsyncPeriodCallback([this] {
         Mutex::Autolock lock(mStateLock);
         return getVsyncPeriod();
@@ -1045,6 +1063,7 @@
         desiredActiveConfigChangeDone();
         return false;
     }
+
     mUpcomingActiveConfig = desiredActiveConfig;
     const auto displayId = display->getId();
     LOG_ALWAYS_FATAL_IF(!displayId);