s = spltty();
s = splcl();
clstop(tp, flag)	struct tty *tp;	int flag;{	int s;	s = spltty();	if (tp->t_state & TS_BUSY) {		if ((tp->t_state & TS_TTSTOP) == 0)			tp->t_state |= TS_FLUSH;	}	splx(s);	return (0);}