hwc/overlay: Introduce padding round between DMA modes.

Introduce a padding round between the DMA line and block modes.
Do this based on whether DMA is actually being used, when block mode
is first requested.

This relieves the driver of doing an UNSET ahead of vsync which could
cause blinks in all such transition scenarios.

This approach should lead to smooth transitions for multiple targets
with the exception of secure videos, where there could be a blink in
any of the different approaches we use.

Change-Id: Ibc0b8d284b5c6ed9291a7cfa7e7f221300a921e2

libhwcomposer/hwc_mdpcomp.cpp

@@ -333,6 +333,12 @@ bool MDPComp::isFrameDoable(hwc_context_t *ctx) {
         return false;
     }
 
+    if(ctx->isPaddingRound) {
+        ctx->isPaddingRound = false;
+        ALOGD_IF(isDebug(), "%s: padding round",__FUNCTION__);
+        return false;
+    }
+
     return true;
 }
 

libhwcomposer/hwc_utils.cpp

@@ -344,6 +344,9 @@ void setListStats(hwc_context_t *ctx,
             yuvCount++;
 
             if(layer->transform & HWC_TRANSFORM_ROT_90) {
+                if(ctx->mOverlay->isPipeTypeAttached(OV_MDP_PIPE_DMA)) {
+                    ctx->isPaddingRound = true;
+                }
                 Overlay::setDMAMode(Overlay::DMA_BLOCK_MODE);
             }
         }

libhwcomposer/hwc_utils.h

@@ -273,6 +273,8 @@ struct hwc_context_t {
     mutable Locker mExtSetLock;
     //Vsync
     struct vsync_state vstate;
+    //Drawing round when we use GPU
+    bool isPaddingRound;
 };
 
 namespace qhwc {

liboverlay/overlay.cpp

@@ -124,6 +124,16 @@ eDest Overlay::nextPipe(eMdpPipeType type, int dpy) {
     return dest;
 }
 
+bool Overlay::isPipeTypeAttached(eMdpPipeType type) {
+    for(int i = 0; i < PipeBook::NUM_PIPES; i++) {
+        if(type == PipeBook::getPipeType((eDest)i) &&
+                mPipeBook[i].mDisplay != PipeBook::DPY_UNUSED) {
+            return true;
+        }
+    }
+    return false;
+}
+
 bool Overlay::commit(utils::eDest dest) {
     bool ret = false;
     int index = (int)dest;

liboverlay/overlay.h

@@ -78,6 +78,10 @@ public:
     static Overlay* getInstance();
     /* Returns available ("unallocated") pipes for a display */
     int availablePipes(int dpy);
+    /* Returns if any of the requested pipe type is attached to any of the
+     * displays
+     */
+    bool isPipeTypeAttached(utils::eMdpPipeType type);
     /* set the framebuffer index for external display */
     void setExtFbNum(int fbNum);
     /* Returns framebuffer index of the current external display */