commit 018e54569f1ad7cf1d6e06db293ba7614358e626
author Naseer Ahmed <naseer@codeaurora.org> Mon Dec 03 14:46:15 2012 -0500
committer Naseer Ahmed <naseer@codeaurora.org> Mon Dec 03 15:36:21 2012 -0500
tree 61b2e501680362d9e574fa6d1b801ff696cd4cc6
parent a25674894733bde53a58a8f3b90dbdc2a4dbdd46

hwc: Avoid MDP composition with alpha scaling

MDP4 supports scaling with alpha, only in RGB pipes.
In some cases this scaling happened with video pipes.
We now fall back to GLES composition for layers that have
alpha and need scaling.

Change-Id: I084355bad1cdb17c7308077b56006c59e75d2042
Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Bug: 7648647

libhwcomposer/hwc_mdpcomp.cpp

diff --git a/libhwcomposer/hwc_mdpcomp.cpp b/libhwcomposer/hwc_mdpcomp.cpp
index 4584207..8616719 100644
--- a/libhwcomposer/hwc_mdpcomp.cpp
+++ b/libhwcomposer/hwc_mdpcomp.cpp
@@ -273,6 +273,11 @@
         return false;
     }
 
+    if(ctx->listStats[HWC_DISPLAY_PRIMARY].needsAlphaScale) {
+        ALOGD_IF(isDebug(), "%s: frame needs alpha downscaling",__FUNCTION__);
+        return false;
+    }
+
     //FB composition on idle timeout
     if(sIdleFallBack) {
         sIdleFallBack = false;

libhwcomposer/hwc_utils.cpp

diff --git a/libhwcomposer/hwc_utils.cpp b/libhwcomposer/hwc_utils.cpp
index ac9a7dc..14de02c 100644
--- a/libhwcomposer/hwc_utils.cpp
+++ b/libhwcomposer/hwc_utils.cpp
@@ -110,6 +110,25 @@
           l->displayFrame.bottom);
 }
 
+static inline bool isAlphaScaled(hwc_layer_1_t const* layer) {
+    int dst_w, dst_h, src_w, src_h;
+
+    hwc_rect_t displayFrame  = layer->displayFrame;
+    hwc_rect_t sourceCrop = layer->sourceCrop;
+
+    dst_w = displayFrame.right - displayFrame.left;
+    dst_h = displayFrame.bottom - displayFrame.top;
+
+    src_w = sourceCrop.right - sourceCrop.left;
+    src_h = sourceCrop.bottom - sourceCrop.top;
+
+    if(((src_w != dst_w) || (src_h != dst_h))) {
+        if(layer->blending != HWC_BLENDING_NONE)
+            return true;
+    }
+    return false;
+}
+
 void setListStats(hwc_context_t *ctx,
         const hwc_display_contents_1_t *list, int dpy) {
 
@@ -118,10 +137,11 @@
     ctx->listStats[dpy].yuvCount = 0;
     ctx->listStats[dpy].yuvIndex = -1;
     ctx->listStats[dpy].skipCount = 0;
+    ctx->listStats[dpy].needsAlphaScale = false;
 
     for (size_t i = 0; i < list->numHwLayers; i++) {
-        private_handle_t *hnd =
-            (private_handle_t *)list->hwLayers[i].handle;
+        hwc_layer_1_t const* layer = &list->hwLayers[i];
+        private_handle_t *hnd = (private_handle_t *)layer->handle;
 
         if(list->hwLayers[i].compositionType == HWC_FRAMEBUFFER_TARGET) {
             continue;
@@ -130,6 +150,9 @@
             ctx->listStats[dpy].skipCount++;
         }
 
+        if(!ctx->listStats[dpy].needsAlphaScale)
+            ctx->listStats[dpy].needsAlphaScale = isAlphaScaled(layer);
+
         if (UNLIKELY(isYuvBuffer(hnd))) {
             ctx->listStats[dpy].yuvCount++;
             ctx->listStats[dpy].yuvIndex = i;
@@ -137,6 +160,7 @@
     }
 }
 
+
 static inline void calc_cut(float& leftCutRatio, float& topCutRatio,
         float& rightCutRatio, float& bottomCutRatio, int orient) {
     if(orient & HAL_TRANSFORM_FLIP_H) {

libhwcomposer/hwc_utils.h

diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index d2445d1..a7de804 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -75,6 +75,7 @@
     //Video specific
     int yuvCount;
     int yuvIndex;
+    bool needsAlphaScale;
 };