Index: main/channel.c
===================================================================
--- a/main/channel.c	(revision 351448)
+++ b/main/channel.c	(working copy)
@@ -3503,6 +3503,16 @@
 	c->timingfunc = func;
 	c->timingdata = data;
 
+	if (func == NULL && rate == 0 && c->fdno == AST_TIMING_FD) {
+		/* Clearing the timing func and setting the rate to 0
+		 * means that we don't want to be reading from the timingfd
+		 * any more. Setting c->fdno to -1 means we won't have any
+		 * errant reads from the timingfd, meaning we won't potentially
+		 * miss any important frames.
+		 */
+		c->fdno = -1;
+	}
+
 	ast_channel_unlock(c);
 
 	return res;