Index: main/channel.c
===================================================================
--- main/channel.c	(revision 320442)
+++ main/channel.c	(working copy)
@@ -1632,13 +1632,21 @@
 	struct ast_channel *chan = obj, *cmp_args = arg;
 	size_t name_len;
 	int ret = CMP_MATCH;
+	int locktry = 10;
 
 	/* This is sort of a hack.  Basically, we're using an arbitrary field
 	 * in ast_channel to pass the name_len for a prefix match.  If this
 	 * gets changed, then the uses of ao2_find() must be changed, too. */
 	name_len = cmp_args->rings;
 
-	ast_channel_lock(chan);
+	/*Deadlock avoidance*/
+	while (ast_channel_trylock(chan)) {
+		if (locktry++ > 10) {
+			ast_debug(1, "Deadlock avoided for ast_channel_cmp_cb '%s'\n", chan->name);
+			return 0;
+		}
+		usleep(1);
+	}
 
 	if (!ast_strlen_zero(cmp_args->name)) { /* match by name */
 		if ((!name_len && strcasecmp(chan->name, cmp_args->name)) ||