tty: make sure to flush any pending work when halting the ldisc

[pandora-kernel.git] / drivers / char / tty_ldisc.c

diff --git a/drivers/char/tty_ldisc.c b/drivers/char/tty_ldisc.c
index 1733d34..e48af9f 100644 (file)
--- a/drivers/char/tty_ldisc.c
+++ b/drivers/char/tty_ldisc.c
@@ -508,8 +508,9 @@ static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
  *     be obtained while the delayed work queue halt ensures that no more
  *     data is fed to the ldisc.
  *
- *     In order to wait for any existing references to complete see
- *     tty_ldisc_wait_idle.
+ *     You need to do a 'flush_scheduled_work()' (outside the ldisc_mutex)
+ *     in order to make sure any currently executing ldisc work is also
+ *     flushed.
  */
 
 static int tty_ldisc_halt(struct tty_struct *tty)
@@ -753,11 +754,14 @@ void tty_ldisc_hangup(struct tty_struct *tty)
         * N_TTY.
         */
        if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+               /* Make sure the old ldisc is quiescent */
+               tty_ldisc_halt(tty);
+               flush_scheduled_work();
+
                /* Avoid racing set_ldisc or tty_ldisc_release */
                mutex_lock(&tty->ldisc_mutex);
                if (tty->ldisc) {       /* Not yet closed */
                        /* Switch back to N_TTY */
-                       tty_ldisc_halt(tty);
                        tty_ldisc_reinit(tty);
                        /* At this point we have a closed ldisc and we want to
                           reopen it. We could defer this to the next open but