Merge "[Lut backend] Fix a bug where we were passing a nullptr to the HWC when we wanted to clear the LUTs." into main

Author: Sally Qi

services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp

@@ -589,28 +589,30 @@ void OutputLayer::writeOutputIndependentGeometryStateToHWC(
 
 void OutputLayer::writeLutToHWC(HWC2::Layer* hwcLayer,
                                 const LayerFECompositionState& outputIndependentState) {
-    if (!outputIndependentState.luts) {
-        return;
-    }
-    auto& lutFileDescriptor = outputIndependentState.luts->getLutFileDescriptor();
-    auto lutOffsets = outputIndependentState.luts->offsets;
-    auto& lutProperties = outputIndependentState.luts->lutProperties;
+    Luts luts;
+    // if outputIndependentState.luts is nullptr, it means we want to clear the LUTs
+    // and we pass an empty Luts object to the HWC.
+    if (outputIndependentState.luts) {
+        auto& lutFileDescriptor = outputIndependentState.luts->getLutFileDescriptor();
+        auto lutOffsets = outputIndependentState.luts->offsets;
+        auto& lutProperties = outputIndependentState.luts->lutProperties;
+
+        std::vector<LutProperties> aidlProperties;
+        aidlProperties.reserve(lutProperties.size());
+        for (size_t i = 0; i < lutOffsets.size(); i++) {
+            LutProperties properties;
+            properties.dimension = static_cast<LutProperties::Dimension>(lutProperties[i].dimension);
+            properties.size = lutProperties[i].size;
+            properties.samplingKeys = {
+                    static_cast<LutProperties::SamplingKey>(lutProperties[i].samplingKey)};
+            aidlProperties.emplace_back(properties);
+        }
 
-    std::vector<LutProperties> aidlProperties;
-    aidlProperties.reserve(lutProperties.size());
-    for (size_t i = 0; i < lutOffsets.size(); i++) {
-        LutProperties properties;
-        properties.dimension = static_cast<LutProperties::Dimension>(lutProperties[i].dimension);
-        properties.size = lutProperties[i].size;
-        properties.samplingKeys = {
-                static_cast<LutProperties::SamplingKey>(lutProperties[i].samplingKey)};
-        aidlProperties.emplace_back(properties);
-    }
 
-    Luts luts;
-    luts.pfd = ndk::ScopedFileDescriptor(dup(lutFileDescriptor.get()));
-    luts.offsets = lutOffsets;
-    luts.lutProperties = std::move(aidlProperties);
+        luts.pfd = ndk::ScopedFileDescriptor(dup(lutFileDescriptor.get()));
+        luts.offsets = lutOffsets;
+        luts.lutProperties = std::move(aidlProperties);
+    }
 
     switch (auto error = hwcLayer->setLuts(luts)) {
         case hal::Error::NONE:

services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp

@@ -901,6 +901,7 @@ struct OutputLayerWriteStateToHWCTest : public OutputLayerTest {
         EXPECT_CALL(*mHwcLayer, setSurfaceDamage(RegionEq(surfaceDamage))).WillOnce(Return(kError));
         EXPECT_CALL(*mHwcLayer, setBlockingRegion(RegionEq(blockingRegion)))
                 .WillOnce(Return(kError));
+        EXPECT_CALL(*mHwcLayer, setLuts(_)).WillOnce(Return(kError));
     }
 
     void expectSetCompositionTypeCall(Composition compositionType) {