tty: Only guarantee termios read safety for throttle/unthrottle

[deliverable/linux.git] / drivers / tty / n_tty.c

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index d0c8805d813171a9f4ae1297fa67b7dbdabcbd90..b78ee464bd09ac431d5484ddaa1efca8c62aaeee 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1518,9 +1518,7 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
                tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
                if (receive_room(tty) >= TTY_THRESHOLD_THROTTLE)
                        break;
-               up_read(&tty->termios_rwsem);
                throttled = tty_throttle_safe(tty);
-               down_read(&tty->termios_rwsem);
                if (!throttled)
                        break;
        }
@@ -2086,9 +2084,7 @@ do_it_again:
                        if (!tty->count)
                                break;
                        n_tty_set_room(tty);
-                       up_read(&tty->termios_rwsem);
                        unthrottled = tty_unthrottle_safe(tty);
-                       down_read(&tty->termios_rwsem);
                        if (!unthrottled)
                                break;
                }