usbd_ratecheck
if (usbd_ratecheck(&sc->atu_rx_notice)) {
if (usbd_ratecheck(&sc->sc_overrun_ntc)) {
int usbd_ratecheck(struct timeval *);
if (usbd_ratecheck(&unp->unp_rx_notice))
if (usbd_ratecheck(&unp->unp_tx_notice))
if (usbd_ratecheck(&unp->unp_intr_notice)) {