1 files changed, 19 insertions, 10 deletions

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 5131bdc9e765..3b3e1f6632d7 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.
  */
 
@@ -2457,20 +2468,20 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
  *	Called without the kernel lock held - fine
  */
 
-static unsigned int gsmld_poll(struct tty_struct *tty, struct file *file,
+static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file,
 							poll_table *wait)
 {
-	unsigned int mask = 0;
+	__poll_t mask = 0;
 	struct gsm_mux *gsm = tty->disc_data;
 
 	poll_wait(file, &tty->read_wait, wait);
 	poll_wait(file, &tty->write_wait, wait);
 	if (tty_hung_up_p(file))
-		mask |= POLLHUP;
+		mask |= EPOLLHUP;
 	if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0)
-		mask |= POLLOUT | POLLWRNORM;
+		mask |= EPOLLOUT | EPOLLWRNORM;
 	if (gsm->dead)
-		mask |= POLLHUP;
+		mask |= EPOLLHUP;
 	return mask;
 }
 
@@ -2955,7 +2966,6 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp)
 static void gsmtty_close(struct tty_struct *tty, struct file *filp)
 {
 	struct gsm_dlci *dlci = tty->driver_data;
-	struct gsm_mux *gsm;
 
 	if (dlci == NULL)
 		return;
@@ -2964,7 +2974,6 @@ static void gsmtty_close(struct tty_struct *tty, struct file *filp)
 	mutex_lock(&dlci->mutex);
 	gsm_destroy_network(dlci);
 	mutex_unlock(&dlci->mutex);
-	gsm = dlci->gsm;
 	if (tty_port_close_start(&dlci->port, tty, filp) == 0)
 		return;
 	gsm_dlci_begin_close(dlci);