MCR_DCD
(void)(*tp->t_linesw->l_modem)(tp, ISSET(msr, MCR_DCD));
sc->sc_msr = sc->sc_msr & ~(MCR_CTS|MCR_DCD|MCR_RI);
sc->sc_msr |= msr & (MCR_CTS|MCR_DCD|MCR_RI);
if (MFP->mf_gpip & MCR_DCD) {
if ((MFP->mf_gpip & MCR_DCD) == 0)
ISSET(sc->sc_msr, MCR_DCD) ? "+" : "-",
sc->sc_msr_dcd = MCR_DCD;
sc->sc_msr_cts = MCR_DCD;
(void)(*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MCR_DCD));