tty: n_hdlc not atomic use tty->flags.

N_HDLC can spoil tty->flags because use not atomic operations on tty->flags.
I use n_hdlc line discipline and it happens.

Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Ilya Zykov 2011-11-07 11:32:46 +04:00 коммит произвёл Greg Kroah-Hartman
Родитель c8381c15b1
Коммит 7962fce9a0
1 изменённых файлов: 3 добавлений и 3 удалений

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@ -417,7 +417,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
__FILE__,__LINE__,tbuf,tbuf->count);
/* Send the next block of data to device */
tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
actual = tty->ops->write(tty, tbuf->buf, tbuf->count);
/* rollback was possible and has been done */
@ -459,7 +459,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
}
if (!tbuf)
tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
/* Clear the re-entry flag */
spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
@ -491,7 +491,7 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty)
return;
if (tty != n_hdlc->tty) {
tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
return;
}