commit 329e7682c63f7ddac92a90b244ed2c44610b882a
author Adrian Salido <salidoa@google.com> Tue Aug 22 00:07:18 2017
committer Adrian Salido <salidoa@google.com> Thu Aug 24 18:39:01 2017
tree 95094ee2586a2a4f25a21073a3cd6757dd6ed6f8
parent ee24aca7b8fbceab1011a4bb36b0baff08d9cdbc

drm_hwcomposer: skip layers with non-premult blending

Tegra driver assumes that all layers with alpha component have premult
alpha. This can cause issues if blending is different since the alpha
component is supposed to be ignored in that case.

Fixes: 62401826
Test: share location in hangouts and drag around map

Change-Id: Iff870697f7efbf5d075a5925d63a8f0f672ee725
Signed-off-by: Adrian Salido <salidoa@google.com>

platformnv.cpp

diff --git a/platformnv.cpp b/platformnv.cpp
index d3e5d70..e680981 100644
--- a/platformnv.cpp
+++ b/platformnv.cpp
@@ -286,7 +286,7 @@
   return 0;
 }
 
-bool PlanStageNvLimits::CheckLayer(DrmHwcLayer *layer) {
+bool PlanStageNvLimits::CheckLayer(size_t zorder, DrmHwcLayer *layer) {
     auto src_w = layer->source_crop.width();
     auto src_h = layer->source_crop.height();
     auto dst_w = layer->display_frame.width();
@@ -295,6 +295,17 @@
     int v_limit;
 
     switch (layer->buffer->format) {
+      case DRM_FORMAT_ARGB8888:
+      case DRM_FORMAT_ABGR8888:
+      case DRM_FORMAT_XBGR8888:
+        // tegra driver assumes any layer with alpha channel has premult
+        // blending, avoid handling it this is not the case. This is not an
+        // issue for bottom-most layer since there's nothing to blend with
+        if (zorder > 0 && layer->blending != DrmHwcBlending::kPreMult)
+          return false;
+
+        v_limit = 2;
+        break;
       case DRM_FORMAT_YVU420:
       case DRM_FORMAT_BGR565:
         v_limit = 4;
@@ -323,7 +334,7 @@
 
   for (auto i = layers.begin(); i != layers.end();) {
     // Skip layer if supported
-    if (CheckLayer(i->second)) {
+    if (CheckLayer(i->first, i->second)) {
       i++;
       continue;
     }

platformnv.h

diff --git a/platformnv.h b/platformnv.h
index 3c1f49e..7e2784f 100644
--- a/platformnv.h
+++ b/platformnv.h
@@ -83,7 +83,7 @@
                       std::map<size_t, DrmHwcLayer *> &layers, DrmCrtc *crtc,
                       std::vector<DrmPlane *> *planes);
  protected:
-  bool CheckLayer(DrmHwcLayer *layer);
+  bool CheckLayer(size_t zorder, DrmHwcLayer *layer);
 };
 }