With content detection off, prefer default frame rate

When content detection is off, or when we have no layer information to
make a decision, prefer the default frame rate.

Bug: 154648391

Test: - Modified a Pixel 4 to turn off content detection, idle, touch,
        and power boost. Confirmed that, without this CL, we have bad
        behavior where calls to setFrameRate() persist after the layer
        goes away, and that this CL fixes that behavior.

- Modified and enhanced the "no layers" unit test in
  RefreshRateConfigsTest.cpp.

Change-Id: I2fd0d64a6ad369580cbb2ebf91cbbed7c31e0281

3 files changed, 26 insertions, 32 deletions

diff --git a/services/surfaceflinger/Scheduler/RefreshRateConfigs.cpp b/services/surfaceflinger/Scheduler/RefreshRateConfigs.cpp
index 8d958df572..5820fc5bde 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateConfigs.cpp
+++ b/services/surfaceflinger/Scheduler/RefreshRateConfigs.cpp
@@ -139,8 +139,8 @@ const RefreshRate& RefreshRateConfigs::getBestRefreshRate(
         return getMinRefreshRateByPolicyLocked();
     }
 
-    if (layers.empty()) {
-        return getCurrentRefreshRateByPolicyLocked();
+    if (layers.empty() || noVoteLayers == layers.size()) {
+        return getMaxRefreshRateByPolicyLocked();
     }
 
     // Only if all layers want Min we should return Min
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index f87c1f8131..fa41bdb90c 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -385,38 +385,33 @@ nsecs_t Scheduler::getDispSyncExpectedPresentTime(nsecs_t now) {
 void Scheduler::registerLayer(Layer* layer) {
     if (!mLayerHistory) return;
 
-    // If the content detection feature is off, all layers are registered at NoVote. We still
-    // keep the layer history, since we use it for other features (like Frame Rate API), so layers
-    // still need to be registered.
-    if (!mUseContentDetection) {
-        mLayerHistory->registerLayer(layer, mRefreshRateConfigs.getMinRefreshRate().getFps(),
-                                     mRefreshRateConfigs.getMaxRefreshRate().getFps(),
-                                     scheduler::LayerHistory::LayerVoteType::NoVote);
-        return;
-    }
+    const auto minFps = mRefreshRateConfigs.getMinRefreshRate().getFps();
+    const auto maxFps = mRefreshRateConfigs.getMaxRefreshRate().getFps();
 
-    // In V1 of content detection, all layers are registered as Heuristic (unless it's wallpaper).
-    if (!mUseContentDetectionV2) {
-        const auto lowFps = mRefreshRateConfigs.getMinRefreshRate().getFps();
-        const auto highFps = layer->getWindowType() == InputWindowInfo::TYPE_WALLPAPER
-                ? lowFps
-                : mRefreshRateConfigs.getMaxRefreshRate().getFps();
-
-        mLayerHistory->registerLayer(layer, lowFps, highFps,
+    if (layer->getWindowType() == InputWindowInfo::TYPE_STATUS_BAR) {
+        mLayerHistory->registerLayer(layer, minFps, maxFps,
+                                     scheduler::LayerHistory::LayerVoteType::NoVote);
+    } else if (!mUseContentDetection) {
+        // If the content detection feature is off, all layers are registered at Max. We still keep
+        // the layer history, since we use it for other features (like Frame Rate API), so layers
+        // still need to be registered.
+        mLayerHistory->registerLayer(layer, minFps, maxFps,
+                                     scheduler::LayerHistory::LayerVoteType::Max);
+    } else if (!mUseContentDetectionV2) {
+        // In V1 of content detection, all layers are registered as Heuristic (unless it's
+        // wallpaper).
+        const auto highFps =
+                layer->getWindowType() == InputWindowInfo::TYPE_WALLPAPER ? minFps : maxFps;
+
+        mLayerHistory->registerLayer(layer, minFps, highFps,
                                      scheduler::LayerHistory::LayerVoteType::Heuristic);
     } else {
         if (layer->getWindowType() == InputWindowInfo::TYPE_WALLPAPER) {
             // Running Wallpaper at Min is considered as part of content detection.
-            mLayerHistory->registerLayer(layer, mRefreshRateConfigs.getMinRefreshRate().getFps(),
-                                         mRefreshRateConfigs.getMaxRefreshRate().getFps(),
+            mLayerHistory->registerLayer(layer, minFps, maxFps,
                                          scheduler::LayerHistory::LayerVoteType::Min);
-        } else if (layer->getWindowType() == InputWindowInfo::TYPE_STATUS_BAR) {
-            mLayerHistory->registerLayer(layer, mRefreshRateConfigs.getMinRefreshRate().getFps(),
-                                         mRefreshRateConfigs.getMaxRefreshRate().getFps(),
-                                         scheduler::LayerHistory::LayerVoteType::NoVote);
         } else {
-            mLayerHistory->registerLayer(layer, mRefreshRateConfigs.getMinRefreshRate().getFps(),
-                                         mRefreshRateConfigs.getMaxRefreshRate().getFps(),
+            mLayerHistory->registerLayer(layer, minFps, maxFps,
                                          scheduler::LayerHistory::LayerVoteType::Heuristic);
         }
     }
diff --git a/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp b/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
index 2b168b2cf2..692f71f8d3 100644
--- a/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
+++ b/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
@@ -340,15 +340,14 @@ TEST_F(RefreshRateConfigsTest, getBestRefreshRate_noLayers) {
             std::make_unique<RefreshRateConfigs>(m60_72_90Device, /*currentConfigId=*/
                                                  HWC_CONFIG_ID_72);
 
-    // If there are not layers, there is not content detection, so return the current
-    // refresh rate.
+    // If there are no layers we select the default frame rate, which is the max of the primary
+    // range.
     auto layers = std::vector<LayerRequirement>{};
-    EXPECT_EQ(mExpected72Config,
+    EXPECT_EQ(mExpected90Config,
               refreshRateConfigs->getBestRefreshRate(layers, /*touchActive*/
                                                      false, /*idle*/ false, &ignored));
 
-    // Current refresh rate can always be changed.
-    refreshRateConfigs->setCurrentConfigId(HWC_CONFIG_ID_60);
+    ASSERT_GE(refreshRateConfigs->setDisplayManagerPolicy({HWC_CONFIG_ID_60, {60, 60}}), 0);
     EXPECT_EQ(mExpected60Config,
               refreshRateConfigs->getBestRefreshRate(layers, /*touchActive*/
                                                      false, /*idle*/ false, &ignored));