hwc: Don't run CABL when HDMI is connected

There is no power benefit with CABL when HDMI is on.

Bug: 9605980
Change-Id: I57b3af493e0af54db520fea04dc3a2d007943b82
Signed-off-by: Iliyan Malchev <malchev@google.com>
diff --git a/libhwcomposer/hwc_utils.cpp b/libhwcomposer/hwc_utils.cpp
index c7756a5..5c67b3e 100644
--- a/libhwcomposer/hwc_utils.cpp
+++ b/libhwcomposer/hwc_utils.cpp
@@ -360,10 +360,19 @@
 }
 
 // Switch ppd on/off for YUV
-static void setYUVProp(hwc_context_t *ctx, int yuvCount) {
+static void configurePPD(hwc_context_t *ctx, int yuvCount) {
     if (!ctx->mCablProp.enabled)
         return;
 
+    // No PPD for external
+    if (ctx->mExtDisplay->isExternalConnected()) {
+        if (ctx->mCablProp.start) {
+            ppdComm("cabl:off", ctx);
+            ctx->mCablProp.start = false;
+        }
+        return;
+    }
+
     if (yuvCount > 0 && !ctx->mCablProp.start) {
         ctx->mCablProp.start = true;
         if(ctx->mCablProp.videoOnly)
@@ -419,7 +428,8 @@
         if(!ctx->listStats[dpy].needsAlphaScale)
             ctx->listStats[dpy].needsAlphaScale = isAlphaScaled(layer);
     }
-    setYUVProp(ctx, ctx->listStats[dpy].yuvCount);
+    if (dpy == HWC_DISPLAY_PRIMARY)
+        configurePPD(ctx, ctx->listStats[dpy].yuvCount);
 }