HWC2: Set composition type before setting buffer

SurfaceFlinger was incorrectly setting the buffer handle before
setting the composition type. This led to cases where the layer was
initially marked as Invalid or Client, allowing HWC2 to ignore the
buffer handle, even though the layer was later changed to Device
before presentation.

Bug: 28814745
Change-Id: I41189495dcb254f04e6b2b329c044301c5cff97c

1 files changed, 31 insertions, 34 deletions

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index ed320cb3d0..2e16d8467f 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -721,53 +721,50 @@ void Layer::setPerFrameData(const sp<const DisplayDevice>& displayDevice) {
         surfaceDamageRegion.dump(LOG_TAG);
     }
 
-    auto compositionType = HWC2::Composition::Invalid;
+    // Sideband layers
     if (mSidebandStream.get()) {
-        compositionType = HWC2::Composition::Sideband;
-        auto error = hwcLayer->setSidebandStream(mSidebandStream->handle());
+        setCompositionType(hwcId, HWC2::Composition::Sideband);
+        ALOGV("[%s] Requesting Sideband composition", mName.string());
+        error = hwcLayer->setSidebandStream(mSidebandStream->handle());
         if (error != HWC2::Error::None) {
             ALOGE("[%s] Failed to set sideband stream %p: %s (%d)",
                     mName.string(), mSidebandStream->handle(),
                     to_string(error).c_str(), static_cast<int32_t>(error));
-            return;
-        }
-    } else {
-        if (mActiveBuffer == nullptr || mActiveBuffer->handle == nullptr) {
-            compositionType = HWC2::Composition::Client;
-            auto error = hwcLayer->setBuffer(nullptr, Fence::NO_FENCE);
-            if (error != HWC2::Error::None) {
-                ALOGE("[%s] Failed to set null buffer: %s (%d)", mName.string(),
-                        to_string(error).c_str(), static_cast<int32_t>(error));
-                return;
-            }
-        } else {
-            if (mPotentialCursor) {
-                compositionType = HWC2::Composition::Cursor;
-            }
-            auto acquireFence = mSurfaceFlingerConsumer->getCurrentFence();
-            auto error = hwcLayer->setBuffer(mActiveBuffer->handle,
-                    acquireFence);
-            if (error != HWC2::Error::None) {
-                ALOGE("[%s] Failed to set buffer %p: %s (%d)", mName.string(),
-                        mActiveBuffer->handle, to_string(error).c_str(),
-                        static_cast<int32_t>(error));
-                return;
-            }
-            // If it's not a cursor, default to device composition
         }
+        return;
     }
 
-    if (mHwcLayers[hwcId].forceClientComposition) {
-        ALOGV("[%s] Forcing Client composition", mName.string());
+    // Client or SolidColor layers
+    if (mActiveBuffer == nullptr || mActiveBuffer->handle == nullptr ||
+            mHwcLayers[hwcId].forceClientComposition) {
+        // TODO: This also includes solid color layers, but no API exists to
+        // setup a solid color layer yet
+        ALOGV("[%s] Requesting Client composition", mName.string());
         setCompositionType(hwcId, HWC2::Composition::Client);
-    } else if (compositionType != HWC2::Composition::Invalid) {
-        ALOGV("[%s] Requesting %s composition", mName.string(),
-                to_string(compositionType).c_str());
-        setCompositionType(hwcId, compositionType);
+        error = hwcLayer->setBuffer(nullptr, Fence::NO_FENCE);
+        if (error != HWC2::Error::None) {
+            ALOGE("[%s] Failed to set null buffer: %s (%d)", mName.string(),
+                    to_string(error).c_str(), static_cast<int32_t>(error));
+        }
+        return;
+    }
+
+    // Device or Cursor layers
+    if (mPotentialCursor) {
+        ALOGV("[%s] Requesting Cursor composition", mName.string());
+        setCompositionType(hwcId, HWC2::Composition::Cursor);
     } else {
         ALOGV("[%s] Requesting Device composition", mName.string());
         setCompositionType(hwcId, HWC2::Composition::Device);
     }
+
+    auto acquireFence = mSurfaceFlingerConsumer->getCurrentFence();
+    error = hwcLayer->setBuffer(mActiveBuffer->handle, acquireFence);
+    if (error != HWC2::Error::None) {
+        ALOGE("[%s] Failed to set buffer %p: %s (%d)", mName.string(),
+                mActiveBuffer->handle, to_string(error).c_str(),
+                static_cast<int32_t>(error));
+    }
 }
 #else
 void Layer::setPerFrameData(const sp<const DisplayDevice>& hw,