ACB_QBITS
if ((acb->flags & ACB_QBITS) != ACB_QREADY)
switch (acb->flags & ACB_QBITS) {
device_xname(sc->sc_dev), acb->flags & ACB_QBITS);
#define ACB_SETQ(e, q) do (e)->flags = ((e)->flags&~ACB_QBITS)|(q); while(0)