SF: Remove refresh_rate_switching flag. With a fix.

ag/9294789 introduce a flag to only allow refresh rate switching on the
devices that have that flag set to true, because it broke devices that
didn't support multiple refresh rates, and Android TV.

LocalDisplayAdapter sets the refresh rate to default when booting the
phone, so no need for that in SF anymore.

Test: Turn off Smooth display (see b/148821456), device doesn't crash.
Test: Install on devices that doesn't have multiple refresh rates.
Test: Run SF unittests.
Test: Turn on all the flags, and run through set of examples:
      Video playback stays at 60.
      Camera stays at 60.
      Maps play at 60.
      Low brightness stays at 90.
      Swappy successfully switches between 60 & 90.
Test: Turn off all the flags, and rerun the examples from previous.
      If applications requested the change, the change is honored,
      otherwise we stay at default (set by DM).
Test: Ask Android TV team to test the patch.
Bug: 148427603
Bug: 148821456

Change-Id: I5bb964572d93e5cb78d7b75054b900917be563b0
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index bc4f805..49a269f 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -530,8 +530,6 @@
     using base::StringAppendF;
     const char* const states[] = {"off", "on"};
 
-    const bool supported = mRefreshRateConfigs.refreshRateSwitchingSupported();
-    StringAppendF(&result, "+  Refresh rate switching: %s\n", states[supported]);
     StringAppendF(&result, "+  Content detection: %s\n", states[mLayerHistory != nullptr]);
 
     StringAppendF(&result, "+  Idle timer: %s\n",
@@ -575,35 +573,44 @@
 }
 
 HwcConfigIndexType Scheduler::calculateRefreshRateType() {
-    if (!mRefreshRateConfigs.refreshRateSwitchingSupported()) {
-        return mRefreshRateConfigs.getCurrentRefreshRate().configId;
+    // This block of the code checks whether any layers used the SetFrameRate API. If they have,
+    // their request should be honored regardless of whether the device has refresh rate switching
+    // turned off.
+    if (layerHistoryHasClientSpecifiedFrameRate()) {
+        if (!mUseContentDetectionV2) {
+            return mRefreshRateConfigs.getRefreshRateForContent(mFeatures.contentRequirements)
+                    .configId;
+        } else {
+            return mRefreshRateConfigs.getRefreshRateForContentV2(mFeatures.contentRequirements)
+                    .configId;
+        }
     }
 
     // If the layer history doesn't have the frame rate specified, use the old path. NOTE:
     // if we remove the kernel idle timer, and use our internal idle timer, this code will have to
     // be refactored.
-    if (!layerHistoryHasClientSpecifiedFrameRate()) {
-        // If Display Power is not in normal operation we want to be in performance mode.
-        // When coming back to normal mode, a grace period is given with DisplayPowerTimer
-        if (!mFeatures.isDisplayPowerStateNormal ||
-            mFeatures.displayPowerTimer == TimerState::Reset) {
-            return mRefreshRateConfigs.getMaxRefreshRateByPolicy().configId;
-        }
+    // If Display Power is not in normal operation we want to be in performance mode.
+    // When coming back to normal mode, a grace period is given with DisplayPowerTimer
+    if (mDisplayPowerTimer &&
+        (!mFeatures.isDisplayPowerStateNormal ||
+         mFeatures.displayPowerTimer == TimerState::Reset)) {
+        return mRefreshRateConfigs.getMaxRefreshRateByPolicy().configId;
+    }
 
-        // As long as touch is active we want to be in performance mode
-        if (mFeatures.touch == TouchState::Active) {
-            return mRefreshRateConfigs.getMaxRefreshRateByPolicy().configId;
-        }
+    // As long as touch is active we want to be in performance mode
+    if (mTouchTimer && mFeatures.touch == TouchState::Active) {
+        return mRefreshRateConfigs.getMaxRefreshRateByPolicy().configId;
+    }
 
-        // If timer has expired as it means there is no new content on the screen
-        if (mFeatures.idleTimer == TimerState::Expired) {
-            return mRefreshRateConfigs.getMinRefreshRateByPolicy().configId;
-        }
+    // If timer has expired as it means there is no new content on the screen
+    if (mIdleTimer && mFeatures.idleTimer == TimerState::Expired) {
+        return mRefreshRateConfigs.getMinRefreshRateByPolicy().configId;
     }
 
     if (!mUseContentDetectionV2) {
-        // If content detection is off we choose performance as we don't know the content fps
+        // If content detection is off we choose performance as we don't know the content fps.
         if (mFeatures.contentDetection == ContentDetectionState::Off) {
+            // TODO(b/148428554): Be careful to not always call this.
             return mRefreshRateConfigs.getMaxRefreshRateByPolicy().configId;
         }
 
@@ -623,6 +630,10 @@
 
 std::optional<HwcConfigIndexType> Scheduler::getPreferredConfigId() {
     std::lock_guard<std::mutex> lock(mFeatureStateLock);
+    // Make sure that the default config ID is first updated, before returned.
+    if (mFeatures.configId.has_value()) {
+        mFeatures.configId = calculateRefreshRateType();
+    }
     return mFeatures.configId;
 }