msm: synx: Enabling async wait support on merged fence

This change enables support to perform async wait on pure local,
pure global, combination of local and global synx fence and nested
merge fence.

Change-Id: I51a1d1998dca997db52bfa5c393bda3e7c2af985
Signed-off-by: Urvesh Rathod <quic_urathod@quicinc.com>

msm/synx/synx.c

@@ -550,11 +550,13 @@ void synx_signal_handler(struct work_struct *cb_dispatch)
 		idx = (IS_ERR_OR_NULL(synx_obj)) ?
 				synx_util_global_idx(h_synx) :
 				synx_obj->global_idx;
-		rc = synx_global_update_status(idx, status);
-		if (rc != SYNX_SUCCESS)
-			dprintk(SYNX_ERR,
-				"global status update of %u failed=%d\n",
-				h_synx, rc);
+		if (synx_global_get_status(idx) == SYNX_STATE_ACTIVE) {
+			rc = synx_global_update_status(idx, status);
+			if (rc != SYNX_SUCCESS)
+				dprintk(SYNX_ERR,
+					"global status update of %u failed=%d\n",
+					h_synx, rc);
+		}
 		/*
 		 * We are decrementing the reference here assuming this code will be
 		 * executed after handle is released. But in case if clients signal
@@ -562,7 +564,8 @@ void synx_signal_handler(struct work_struct *cb_dispatch)
 		 * one reference thus deleting the global idx. As of now clients cannot
 		 * signal dma fence.
 		 */
-		synx_global_put_ref(idx);
+		if (IS_ERR_OR_NULL(synx_obj))
+			synx_global_put_ref(idx);
 	}
 
 	/*
@@ -595,7 +598,15 @@ void synx_signal_handler(struct work_struct *cb_dispatch)
 			rc = synx_native_signal_fence(synx_obj, status);
 	}
 
-	if (rc == SYNX_SUCCESS && !synx_util_is_merged_object(synx_obj))
+	if (rc != SYNX_SUCCESS) {
+		mutex_unlock(&synx_obj->obj_lock);
+		dprintk(SYNX_ERR,
+			"failed to signal fence %u with err=%d\n",
+			h_synx, rc);
+		goto fail;
+	}
+
+	if (rc == SYNX_SUCCESS)
 		rc = synx_native_signal_core(synx_obj, status,
 			(signal_cb->flag & SYNX_SIGNAL_FROM_CALLBACK) ?
 			true : false, signal_cb->ext_sync_id);
@@ -1040,6 +1051,10 @@ int synx_merge(struct synx_session *session,
 		goto clean_up;
 	}
 
+	rc = synx_util_add_callback(synx_obj, *params->h_merged_obj);
+	if (rc != SYNX_SUCCESS)
+		goto clear;
+
 	rc = synx_util_init_handle(client, synx_obj,
 			params->h_merged_obj, map_entry);
 	if (rc) {