SMF_CARD_PRESENT
if (ISSET(sc->sc_flags, SMF_CARD_PRESENT)) {
card_present = ISSET(sc->sc_flags, SMF_CARD_PRESENT);
SET(sc->sc_flags, SMF_CARD_PRESENT);
CLR(sc->sc_flags, SMF_CARD_PRESENT);
CLR(sc->sc_flags, SMF_CARD_PRESENT);
card_present = ISSET(sc->sc_flags, SMF_CARD_PRESENT);