Add retry for vchiq init. Needed in some cases when using CMA

drivers/misc/vc04_services/interface/vchiq_arm/vchiq_kern_lib.c

@@ -68,20 +68,31 @@ vchiq_blocking_bulk_transfer(VCHIQ_SERVICE_HANDLE_T handle, void *data,
 *   vchiq_initialise
 *
 ***************************************************************************/
-
+#define VCHIQ_INIT_RETRIES 10
 VCHIQ_STATUS_T vchiq_initialise(VCHIQ_INSTANCE_T *instanceOut)
 {
 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
 	VCHIQ_STATE_T *state;
 	VCHIQ_INSTANCE_T instance = NULL;
+        int i;
 
 	vchiq_log_trace(vchiq_core_log_level, "%s called", __func__);
 
-	state = vchiq_get_state();
-	if (!state) {
+        /* VideoCore may not be ready due to boot up timing.
+           It may never be ready if kernel and firmware are mismatched, so don't block forever. */
+        for (i=0; i<VCHIQ_INIT_RETRIES; i++) {
+		state = vchiq_get_state();
+		if (state)
+			break;
+		udelay(500);
+	}
+	if (i==VCHIQ_INIT_RETRIES) {
 		vchiq_log_error(vchiq_core_log_level,
 			"%s: videocore not initialized\n", __func__);
 		goto failed;
+	} else if (i>0) {
+		vchiq_log_warning(vchiq_core_log_level,
+			"%s: videocore initialized after %d retries\n", __func__, i);
 	}
 
 	instance = kzalloc(sizeof(*instance), GFP_KERNEL);