diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 48e791d95f76..db6728c7d1a9 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1451,6 +1451,10 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
  *	in which case an opening port goes back to closed and a closing port
  *	is simply put into closed state (any further frames from the other
  *	end will get a DM response)
+ *
+ *	Some control dlci can stay in ADM mode with other dlci working just
+ *	fine. In that case we can just keep the control dlci open after the
+ *	DLCI_OPENING retries time out.
  */
 
 static void gsm_dlci_t1(struct timer_list *t)
@@ -1464,8 +1468,15 @@ static void gsm_dlci_t1(struct timer_list *t)
 		if (dlci->retries) {
 			gsm_command(dlci->gsm, dlci->addr, SABM|PF);
 			mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
-		} else
+		} else if (!dlci->addr && gsm->control == (DM | PF)) {
+			if (debug & 8)
+				pr_info("DLCI %d opening in ADM mode.\n",
+					dlci->addr);
+			gsm_dlci_open(dlci);
+		} else {
 			gsm_dlci_close(dlci);
+		}
+
 		break;
 	case DLCI_CLOSING:
 		dlci->retries--;
@@ -1483,8 +1494,8 @@ static void gsm_dlci_t1(struct timer_list *t)
  *	@dlci: DLCI to open
  *
  *	Commence opening a DLCI from the Linux side. We issue SABM messages
- *	to the modem which should then reply with a UA, at which point we
- *	will move into open state. Opening is done asynchronously with retry
+ *	to the modem which should then reply with a UA or ADM, at which point
+ *	we will move into open state. Opening is done asynchronously with retry
  *	running off timers and the responses.
  */