Index: channels/sig_analog.c
===================================================================
--- channels/sig_analog.c	(revision 206802)
+++ channels/sig_analog.c	(working copy)
@@ -289,10 +289,13 @@
 
 static int analog_alloc_sub(struct analog_pvt *p, enum analog_sub x)
 {
-	p->subs[x].allocd = 1;
-	if (p->calls->allocate_sub)
-		return p->calls->allocate_sub(p->chan_pvt, x);
-
+	if (p->calls->allocate_sub) {
+		int res = p->calls->allocate_sub(p->chan_pvt, x);
+		if (!res) {
+			p->subs[x].allocd = 1;
+		}
+		return res;
+	}
 	return 0;
 }