commit 57e3c819bb6f700eb3bdc7ef38e2d3691587c1a0
author Amara Venkata Mastan Manoj Kumar <manojavm@codeaurora.org> Fri Jan 11 13:36:33 2013 -0800
committer Amara Venkata Mastan Manoj Kumar <manojavm@codeaurora.org> Wed Jan 16 10:08:10 2013 -0800
tree b71886ca9c9ebaa80c1503760c152d0038665218
parent f8bba3b8abe8b0f2e018f3baa2d12a17298217db

hwc: Invoke commit ioctl even if there are no app layers

  Android has scenarios where it calls HWC::prepare and HWC::set
  without any application layers. In such cases, for power
  optimization, user space avoids  calling PLAY
  (on FB - since there is no new content drawn) and COMMIT ioctls.
  But we might have called UNSET on mdp pipes used for the previous
  frame. As per the current MDP design, these freed pipes will not
  be unstaged unless atleast a COMMIT ioctl is called on that mixer.

Change-Id: I7f7574b2e589e80c4926533066e35784bb29b4a5
CRs-Fixed: 437736

libhwcomposer/hwc.cpp

diff --git a/libhwcomposer/hwc.cpp b/libhwcomposer/hwc.cpp
index ba84580..84b1100 100644
--- a/libhwcomposer/hwc.cpp
+++ b/libhwcomposer/hwc.cpp
@@ -125,7 +125,6 @@
         hwc_display_contents_1_t *list) {
     hwc_context_t* ctx = (hwc_context_t*)(dev);
     const int dpy = HWC_DISPLAY_PRIMARY;
-
     if (LIKELY(list && list->numHwLayers > 1) &&
         ctx->dpyAttr[dpy].isActive) {
 
@@ -306,14 +305,14 @@
     int ret = 0;
     const int dpy = HWC_DISPLAY_PRIMARY;
 
-    if (LIKELY(list && list->numHwLayers > 1) &&
-        ctx->dpyAttr[dpy].isActive) {
+    if (LIKELY(list) && ctx->dpyAttr[dpy].isActive) {
         uint32_t last = list->numHwLayers - 1;
         hwc_layer_1_t *fbLayer = &list->hwLayers[last];
         int fd = -1; //FenceFD from the Copybit(valid in async mode)
         if(ctx->mCopyBit[dpy])
             ctx->mCopyBit[dpy]->draw(ctx, list, dpy, &fd);
-        hwc_sync(ctx, list, dpy, fd);
+        if(list->numHwLayers > 1)
+            hwc_sync(ctx, list, dpy, fd);
         if (!VideoOverlay::draw(ctx, list, dpy)) {
             ALOGE("%s: VideoOverlay::draw fail!", __FUNCTION__);
             ret = -1;
@@ -327,7 +326,8 @@
         //always. Last layer is always FB
         private_handle_t *hnd = (private_handle_t *)fbLayer->handle;
         if(fbLayer->compositionType == HWC_FRAMEBUFFER_TARGET && hnd) {
-            if(!(fbLayer->flags & HWC_SKIP_LAYER)) {
+            if(!(fbLayer->flags & HWC_SKIP_LAYER) &&
+                (list->numHwLayers > 1)) {
                 if (!ctx->mFBUpdate[dpy]->draw(ctx, fbLayer)) {
                     ALOGE("%s: FBUpdate::draw fail!", __FUNCTION__);
                     ret = -1;
@@ -349,8 +349,7 @@
 
     Locker::Autolock _l(ctx->mExtSetLock);
 
-    if (LIKELY(list && list->numHwLayers > 1) &&
-        ctx->dpyAttr[dpy].isActive &&
+    if (LIKELY(list) && ctx->dpyAttr[dpy].isActive &&
         ctx->dpyAttr[dpy].connected) {
         uint32_t last = list->numHwLayers - 1;
         hwc_layer_1_t *fbLayer = &list->hwLayers[last];
@@ -358,7 +357,8 @@
         if(ctx->mCopyBit[dpy])
             ctx->mCopyBit[dpy]->draw(ctx, list, dpy, &fd);
 
-        hwc_sync(ctx, list, dpy, fd);
+        if(list->numHwLayers > 1)
+            hwc_sync(ctx, list, dpy, fd);
 
         if (!VideoOverlay::draw(ctx, list, dpy)) {
             ALOGE("%s: VideoOverlay::draw fail!", __FUNCTION__);
@@ -367,7 +367,8 @@
 
         private_handle_t *hnd = (private_handle_t *)fbLayer->handle;
         if(fbLayer->compositionType == HWC_FRAMEBUFFER_TARGET &&
-                !(fbLayer->flags & HWC_SKIP_LAYER) && hnd) {
+                !(fbLayer->flags & HWC_SKIP_LAYER) && hnd &&
+                (list->numHwLayers > 1)) {
             if (!ctx->mFBUpdate[dpy]->draw(ctx, fbLayer)) {
                 ALOGE("%s: FBUpdate::draw fail!", __FUNCTION__);
                 ret = -1;