1 files changed, 25 insertions, 13 deletions

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 525ee53..7712091 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -530,14 +530,17 @@ static int tty_ldisc_wait_idle(struct tty_struct *tty, long timeout)
 /**
  *	tty_ldisc_halt		-	shut down the line discipline
  *	@tty: tty device
+ *	@o_tty: paired pty device (can be NULL)
  *	@pending: returns true if work was scheduled when cancelled
  *		  (can be set to NULL)
+ *	@o_pending: returns true if work was scheduled when cancelled
+ *		    (can be set to NULL)
  *	@timeout: # of jiffies to wait for ldisc refs to be released
  *
- *	Shut down the line discipline and work queue for this tty device.
- *	The TTY_LDISC flag being cleared ensures no further references can
- *	be obtained while the delayed work queue halt ensures that no more
- *	data is fed to the ldisc.
+ *	Shut down the line discipline and work queue for this tty device and
+ *	its paired pty (if exists). Clearing the TTY_LDISC flag ensures
+ *	no further references can be obtained while the work queue halt
+ *	ensures that no more data is fed to the ldisc.
  *
  *	Furthermore, guarantee that existing ldisc references have been
  *	released, which in turn, guarantees that no future buffer work
@@ -548,19 +551,32 @@ static int tty_ldisc_wait_idle(struct tty_struct *tty, long timeout)
  *	flushed.
  */
 
-static int tty_ldisc_halt(struct tty_struct *tty, int *pending, long timeout)
+static int tty_ldisc_halt(struct tty_struct *tty, struct tty_struct *o_tty,
+			  int *pending, int *o_pending, long timeout)
 {
-	int scheduled, retval;
+	int scheduled, o_scheduled, retval;
 
 	clear_bit(TTY_LDISC, &tty->flags);
+	if (o_tty)
+		clear_bit(TTY_LDISC, &o_tty->flags);
+
 	retval = tty_ldisc_wait_idle(tty, timeout);
+	if (!retval && o_tty)
+		retval = tty_ldisc_wait_idle(o_tty, timeout);
 	if (retval)
 		return retval;
 
 	scheduled = cancel_work_sync(&tty->port->buf.work);
 	set_bit(TTY_LDISC_HALTED, &tty->flags);
+	if (o_tty) {
+		o_scheduled = cancel_work_sync(&o_tty->port->buf.work);
+		set_bit(TTY_LDISC_HALTED, &o_tty->flags);
+	}
+
 	if (pending)
 		*pending = scheduled;
+	if (o_tty && o_pending)
+		*o_pending = o_scheduled;
 	return 0;
 }
 
@@ -702,9 +718,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 	 *	parallel to the change and re-referencing the tty.
 	 */
 
-	retval = tty_ldisc_halt(tty, &work, 5 * HZ);
-	if (!retval && o_tty)
-		retval = tty_ldisc_halt(o_tty, &o_work, 5 * HZ);
+	retval = tty_ldisc_halt(tty, o_tty, &work, &o_work, 5 * HZ);
 
 	/*
 	 * Wait for ->hangup_work and ->buf.work handlers to terminate.
@@ -965,12 +979,10 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
 	 * race with the set_ldisc code path.
 	 */
 
-	tty_ldisc_halt(tty, NULL, MAX_SCHEDULE_TIMEOUT);
+	tty_ldisc_halt(tty, o_tty, NULL, NULL, MAX_SCHEDULE_TIMEOUT);
 	tty_ldisc_flush_works(tty);
-	if (o_tty) {
-		tty_ldisc_halt(o_tty, NULL, MAX_SCHEDULE_TIMEOUT);
+	if (o_tty)
 		tty_ldisc_flush_works(o_tty);
-	}
 
 	tty_lock_pair(tty, o_tty);
 	/* This will need doing differently if we need to lock */