tty: Clarify multiple-references comment in TIOCSETD ioctl

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 5819667f5bdb..75fa99978348 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -570,13 +570,15 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
                 tty_ldisc_restore(tty, old_ldisc);
         }
 
-        /* At this point we hold a reference to the new ldisc and a
-           a reference to the old ldisc. If we ended up flipping back
-           to the existing ldisc we have two references to it */
-
         if (tty->ldisc->ops->num != old_ldisc->ops->num && tty->ops->set_ldisc)
                 tty->ops->set_ldisc(tty);
 
+        /* At this point we hold a reference to the new ldisc and a
+           reference to the old ldisc, or we hold two references to
+           the old ldisc (if it was restored as part of error cleanup
+           above). In either case, releasing a single reference from
+           the old ldisc is correct. */
+
         tty_ldisc_put(old_ldisc);
 
         /*