Avoid intermediate composition when Overlay Support is disabled.

When overlay support is disabled, client should take care of blending
all layers together and giving us the final output. Ideally, we
should be able to scanout the client buffer instead of rendering
to another offscreen target and scanning it out. Now, we try to
scanout the buffer if possible directly instead of rendering it
to an intermediate buffer.

Jira: None.
Test: No regressions on Linux and Android.

Signed-off-by: Kalyan Kondapally <kalyan.kondapally@intel.com>

diff --git a/common/display/displayplanemanager.cpp b/common/display/displayplanemanager.cpp
index 01f9cfd..107f24d 100644 (file)
--- a/common/display/displayplanemanager.cpp
+++ b/common/display/displayplanemanager.cpp
@@ -139,6 +139,7 @@ std::tuple<bool, DisplayPlaneStateList> DisplayPlaneManager::ValidateLayers(
   auto layer_begin = layers.begin();
   auto layer_end = layers.end();
   bool render_layers = false;
+  bool force_gpu = false;
 #ifndef DISABLE_OVERLAY_USAGE
   // Check if the combination of layers is same as last frame
   // and if so check if we can use the result of last validation.
@@ -152,6 +153,11 @@ std::tuple<bool, DisplayPlaneStateList> DisplayPlaneManager::ValidateLayers(
   // Dont use cache next frame if we are doing modeset now. With modeset
   // we force all layers for 3D composition.
   use_cache_ = !pending_modeset;
+#else
+  // When overlay support is disabled, client should take care of blending
+  // all layers together and giving us the final output. If thats not
+  // the case lets handle it here.
+  force_gpu = layers.size() > 1;
 #endif
   // We start off with Primary plane.
   DisplayPlane *current_plane = primary_plane_.get();
@@ -162,7 +168,7 @@ std::tuple<bool, DisplayPlaneStateList> DisplayPlaneManager::ValidateLayers(
   ++layer_begin;
   // Lets ensure we fall back to GPU composition in case
   // primary layer cannot be scanned out directly.
-  if ((pending_modeset && layers.size() > 1) ||
+  if ((pending_modeset && layers.size() > 1) || force_gpu ||
       FallbacktoGPU(current_plane, primary_layer, commit_planes)) {
     DisplayPlaneState &last_plane = composition.back();
     render_layers = true;
@@ -499,10 +505,6 @@ void DisplayPlaneManager::ValidateCachedLayers(
 bool DisplayPlaneManager::FallbacktoGPU(
     DisplayPlane *target_plane, OverlayLayer *layer,
     const std::vector<OverlayPlane> &commit_planes) const {
-#ifdef DISABLE_OVERLAY_USAGE
-  return true;
-#endif
-
   if (!target_plane->ValidateLayer(layer))
     return true;