hwc: Add a new check for DMA state change

Add a check to bail out of MDP composition in cases when we need
to switch the DMA state.

Change-Id: Iab3978df77d7f0e7cee28603189292504706c463
diff --git a/libhwcomposer/hwc_mdpcomp.cpp b/libhwcomposer/hwc_mdpcomp.cpp
index 2904e6f..baeb1b9 100644
--- a/libhwcomposer/hwc_mdpcomp.cpp
+++ b/libhwcomposer/hwc_mdpcomp.cpp
@@ -466,7 +466,15 @@
                      __FUNCTION__,mDpy);
             ret = false;
         }
+    } else if (ctx->isDMAStateChanging) {
+        // Bail out if a padding round has been invoked in order to switch DMA
+        // state to block mode. We need this to cater for the case when a layer
+        // requires rotation in the current frame.
+        ALOGD_IF(isDebug(), "%s: padding round invoked to switch DMA state",
+                __FUNCTION__);
+        return false;
     }
+
     return ret;
 }