commit fc2acbe75484dea7197b75d0ef9889f78398b06b
author Saurabh Shah <saurshah@codeaurora.org> Fri Aug 17 19:47:52 2012 -0700
committer Iliyan Malchev <malchev@google.com> Mon Aug 27 13:53:40 2012 -0700
tree 14070c0de4a3cdb23e0cdd560baa22f7c0cc903b
parent 94822ee87c6b3de1af7ca25c04f868f7e29e4ca2

hwc/fb/overlay: wait for fbpost and pan display

Draw sequence in hwc_set
--eglSwapBuffers
--wait for fb_post. Its ok to draw to External only at this point.
--draw to external   | Parallel with PAN
--commit to external | Parallel with PAN
--wait for pan (happening in fb_post) to finish.

Call MSMFB_OVERLAY_SET ioctl only when params change.

These thing together ensure a correct sequence and should fix tearing and
stuttering, the latter assuming there are no other display pipeline delays.

Acked-by: Arun Kumar K.R <akumarkr@codeaurora.org>

Change-Id: Ibb0ad8485fa6b30dc6ac07ae8b25a760941c08ce

liboverlay/overlayMdp.cpp

diff --git a/liboverlay/overlayMdp.cpp b/liboverlay/overlayMdp.cpp
index c795b99..d161f4a 100644
--- a/liboverlay/overlayMdp.cpp
+++ b/liboverlay/overlayMdp.cpp
@@ -131,15 +131,17 @@
 bool MdpCtrl::set() {
     //deferred calcs, so APIs could be called in any order.
     doTransform();
-    if(!mdp_wrapper::setOverlay(mFd.getFD(), mOVInfo)) {
-        ALOGE("MdpCtrl failed to setOverlay, restoring last known "
-                "good ov info");
-        mdp_wrapper::dump("== Bad OVInfo is: ", mOVInfo);
-        mdp_wrapper::dump("== Last good known OVInfo is: ", mLkgo);
-        this->restore();
-        return false;
+    if(this->ovChanged()) {
+        if(!mdp_wrapper::setOverlay(mFd.getFD(), mOVInfo)) {
+            ALOGE("MdpCtrl failed to setOverlay, restoring last known "
+                  "good ov info");
+            mdp_wrapper::dump("== Bad OVInfo is: ", mOVInfo);
+            mdp_wrapper::dump("== Last good known OVInfo is: ", mLkgo);
+            this->restore();
+            return false;
+        }
+        this->save();
     }
-    this->save();
     return true;
 }