[PATCH] tty_io.c balance tty_ldisc_ref()

tty_ldisc_deref() should only be called when tty_ldisc_ref() succeeds
otherwise it triggers a BUG().  There's already a function
tty_ldisc_flush() that flushes properly.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 6 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index a928f6af52f..47a6eacb10b 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -3335,18 +3335,13 @@ static void __do_SAK(struct work_struct *work)
         int session;
         int             i;
         struct file     *filp;
-        struct tty_ldisc *disc;
         struct fdtable *fdt;
         
         if (!tty)
                 return;
         session = tty->session;
         
-        /* We don't want an ldisc switch during this */
-        disc = tty_ldisc_ref(tty);
-        if (disc && disc->flush_buffer)
-                disc->flush_buffer(tty);
-        tty_ldisc_deref(disc);
+        tty_ldisc_flush(tty);
 
         if (tty->driver->flush_buffer)
                 tty->driver->flush_buffer(tty);