EPCR
OUTB(dp, EPCR, which | EPCR_ERPRR, errp, usberr);
IN(dp, EPCR, sizeof (epcr), &epcr, errp, usberr);
OUTB(dp, EPCR, 0, errp, usberr);
OUTB(dp, EPCR, which | EPCR_WEP | EPCR_ERPRW, errp, usberr);
IN(dp, EPCR, 1, &epcr, errp, usberr);
OUTB(dp, EPCR, 0, errp, usberr);