+ /*
+ * Loop waiting for input, checking that nothing disasterous
+ * happens in the meantime.
+ */
+ s = spltty();
+ for (;;) {
+ if (tp != (struct tty *) sc->sc_devp || tp->t_line != PPPDISC) {
+ splx(s);
+ return 0;
+ }
+ if (sc->sc_inq.ifq_head != NULL)
+ break;
+ if ((tp->t_state & TS_CARR_ON) == 0 && (tp->t_cflag & CLOCAL) == 0
+ && (tp->t_state & TS_ISOPEN)) {
+ splx(s);
+ return 0; /* end of file */
+ }