hwc: more error checks

-- numHwLayers==1 means that there is only the FB_TARGET which HWC shouldn't
   draw. Also check for blank in set.  Checking for this in prepare prevents us
   from acquiring pipes.
-- add null check for private handle
-- print out vsync timestamp data on error

bug: 7274417
related-to-bug: 7288769
Change-Id: I8dae0d0748c5226fdc33ed8f5cc5259835dec2de
Signed-off-by: Iliyan Malchev <malchev@google.com>

libgralloc/framebuffer.cpp

@@ -113,7 +113,7 @@ static int fb_post(struct framebuffer_device_t* dev, buffer_handle_t buffer)
         m->info.yoffset = hnd->offset / m->finfo.line_length;
         m->commit.var = m->info;
         if (ioctl(m->framebuffer->fd, MSMFB_DISPLAY_COMMIT, &m->commit) == -1) {
-            ALOGE("%s: FBIOPUT_VSCREENINFO failed for external, err: %s", __FUNCTION__,
+            ALOGE("%s: MSMFB_DISPLAY_COMMIT ioctl failed, err: %s", __FUNCTION__,
                     strerror(errno));
             return -errno;
         }

libhwcomposer/hwc.cpp

@@ -87,7 +87,7 @@ static int hwc_prepare_primary(hwc_composer_device_1 *dev,
         hwc_display_contents_1_t *list) {
     hwc_context_t* ctx = (hwc_context_t*)(dev);
     ctx->overlayInUse[HWC_DISPLAY_PRIMARY] = false;
-    if (LIKELY(list && list->numHwLayers)) {
+    if (LIKELY(list && list->numHwLayers > 1)) {
         uint32_t last = list->numHwLayers - 1;
         hwc_layer_1_t *fblayer = &list->hwLayers[last];
         setListStats(ctx, list, HWC_DISPLAY_PRIMARY);
@@ -108,7 +108,7 @@ static int hwc_prepare_external(hwc_composer_device_1 *dev,
     hwc_context_t* ctx = (hwc_context_t*)(dev);
     ctx->overlayInUse[HWC_DISPLAY_EXTERNAL] = false;
 
-    if (LIKELY(list && list->numHwLayers) &&
+    if (LIKELY(list && list->numHwLayers > 1) &&
         ctx->dpyAttr[HWC_DISPLAY_EXTERNAL].isActive &&
         ctx->dpyAttr[HWC_DISPLAY_EXTERNAL].connected) {
 
@@ -256,7 +256,8 @@ static int hwc_set_primary(hwc_context_t *ctx, hwc_display_contents_1_t* list) {
     if(!ctx->overlayInUse[HWC_DISPLAY_PRIMARY])
         ctx->mOverlay[HWC_DISPLAY_PRIMARY]->setState(ovutils::OV_CLOSED);
 
-    if (LIKELY(list && list->numHwLayers)) {
+    if (LIKELY(list && list->numHwLayers > 1) &&
+        ctx->dpyAttr[HWC_DISPLAY_PRIMARY].isActive) {
         uint32_t last = list->numHwLayers - 1;
         hwc_layer_1_t *fbLayer = &list->hwLayers[last];
 
@@ -280,7 +281,7 @@ static int hwc_set_external(hwc_context_t *ctx,
     if(!ctx->overlayInUse[HWC_DISPLAY_EXTERNAL])
         ctx->mOverlay[HWC_DISPLAY_EXTERNAL]->setState(ovutils::OV_CLOSED);
 
-    if (LIKELY(list && list->numHwLayers) &&
+    if (LIKELY(list && list->numHwLayers > 1) &&
         ctx->dpyAttr[HWC_DISPLAY_EXTERNAL].isActive &&
         ctx->dpyAttr[HWC_DISPLAY_EXTERNAL].connected) {
         uint32_t last = list->numHwLayers - 1;

libhwcomposer/hwc_uimirror.cpp

@@ -63,6 +63,10 @@ bool UIMirrorOverlay::configure(hwc_context_t *ctx, hwc_layer_1_t *layer)
         // Set overlay state
         ov.setState(sState);
         private_handle_t *hnd = (private_handle_t *)layer->handle;
+        if (!hnd) {
+            ALOGE("%s:NULL private handle for layer!", __FUNCTION__);
+            return false;
+        }
         ovutils::Whf info(hnd->width, hnd->height, hnd->format, hnd->size);
         // Determine the RGB pipe for UI depending on the state
         ovutils::eDest dest = ovutils::OV_PIPE0;

libhwcomposer/hwc_vsync.cpp

@@ -109,8 +109,9 @@ static void *vsync_loop(void *param)
        if (!strncmp(str, "VSYNC=", strlen("VSYNC="))) {
           cur_timestamp = strtoull(str + strlen("VSYNC="), NULL, 0);
        } else {
-          ALOGE ("FATAL:%s:timestamp data not in correct format",
-                                                 __FUNCTION__);
+          ALOGE ("FATAL: %s: vsync timestamp not in correct format: [%s]",
+                  __FUNCTION__,
+                  str);
        }
        // send timestamp to HAL
        ALOGD_IF (VSYNC_DEBUG, "%s: timestamp %llu sent to HWC for %s",