TSA_CARR_ON
error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "nmdopn", 0);
error = tsleep(TSA_CARR_ON(tp), PCATCH, "siodcd", 0);
wakeup(TSA_CARR_ON(tp)); /* restart any wopeners */
wakeup(TSA_CARR_ON(tp));
wakeup(TSA_CARR_ON(tp));
error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "ttydcd", 0);
wakeup(TSA_CARR_ON(tp));
error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "ptsopn", 0);