hwc: use triple buffer hint for overlay layers for debug

This is a cheat to discriminate between blit layers and real overlay engine
layers in dumpsys SurfaceFlinger.

This patch is benign for an OVERLAY type layer the hints field should have bit 1
set when using dss overlays, and clear when it was blitted.

Ported from p-ics-mr1:
1f4cf8b hwc: use triple buffer for overlay layers

Change-Id: I7a9afed74c0b2e44bf08d3611775be28530378a1
Signed-off-by: Tony Lofthouse <a0741364@ti.com>
(cherry picked from commit 407ca87c9557dfd381f7ce765f080503722e7fd7)

1 files changed, 7 insertions, 0 deletions

diff --git a/hwc/hwc.c b/hwc/hwc.c
index d40c673..664b55f 100644
--- a/hwc/hwc.c
+++ b/hwc/hwc.c
@@ -1540,6 +1540,7 @@ static int blit_layers(omap4_hwc_device_t *hwc_dev, hwc_layer_list_t *list, int
         if (list->hwLayers[i].compositionType != HWC_OVERLAY) {
             list->hwLayers[i].compositionType = HWC_OVERLAY;
             //ALOGI("blitting layer %d", i);
+            list->hwLayers[i].hints &= ~HWC_HINT_TRIPLE_BUFFER;
         }
         list->hwLayers[i].hints &= ~HWC_HINT_CLEAR_FB;
     }
@@ -1652,6 +1653,12 @@ static int omap4_hwc_prepare(struct hwc_composer_device_1 *dev, size_t numDispla
             /* render via DSS overlay */
             mem_used += mem1d(handle);
             layer->compositionType = HWC_OVERLAY;
+            /*
+             * This hint will not be used in vanilla ICS, but maybe in
+             * JellyBean, it is useful to distinguish between blts and true
+             * overlays
+             */
+            layer->hints |= HWC_HINT_TRIPLE_BUFFER;
 
             /* clear FB above all opaque layers if rendering via SGX */
             if (hwc_dev->use_sgx && !is_BLENDED(layer))