/* Locking: output_lock to protect column state and space left (also, this is called from n_tty_write under the tty layer write lock)  */
static int process_output(unsigned char c, struct tty_struct *tty)
/* Locking: output_lock to protect column state and space left (also, this is called from n_tty_write under the tty layer write lock)  */
static int process_output(unsigned char c, struct tty_struct *tty)
{
	int	space, retval;
	mutex_lock(&tty->output_lock);
	space = tty_write_room(tty);
	retval = do_output_char(c, tty, space);
	mutex_unlock(&tty->output_lock);
	if (retval < 0)
		return -1;
	else
		return 0;
}