static void tty_write_unlock(struct tty_struct *tty)
{
	mutex_unlock(&tty->atomic_write_lock);
	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
}
static void tty_write_unlock(struct tty_struct *tty)
{
	mutex_unlock(&tty->atomic_write_lock);
	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
}