diff --git a/[refs] b/[refs]
index 03c0b62bca9b..6ac5076cfdbb 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a4c9fe8daf88b27f81be8022d49c073d37fe645e
+refs/heads/master: f17141fdd407de78379222dd59d6f161437db4c8
diff --git a/trunk/drivers/tty/n_gsm.c b/trunk/drivers/tty/n_gsm.c
index ed429082304d..8d7766bfef87 100644
--- a/trunk/drivers/tty/n_gsm.c
+++ b/trunk/drivers/tty/n_gsm.c
@@ -2003,6 +2003,7 @@ void gsm_cleanup_mux(struct gsm_mux *gsm)
 	int i;
 	struct gsm_dlci *dlci = gsm->dlci[0];
 	struct gsm_msg *txq;
+	struct gsm_control *gc;
 
 	gsm->dead = 1;
 
@@ -2016,6 +2017,13 @@ void gsm_cleanup_mux(struct gsm_mux *gsm)
 	spin_unlock(&gsm_mux_lock);
 	WARN_ON(i == MAX_MUX);
 
+	/* In theory disconnecting DLCI 0 is sufficient but for some
+	   modems this is apparently not the case. */
+	if (dlci) {
+		gc = gsm_control_send(gsm, CMD_CLD, NULL, 0);
+		if (gc)
+			gsm_control_wait(gsm, gc);
+	}
 	del_timer_sync(&gsm->t2_timer);
 	/* Now we are sure T2 has stopped */
 	if (dlci) {