XHCI_USBSTS
bus_read_4(res, offs + XHCI_USBSTS);
status = XREAD4(sc, oper, XHCI_USBSTS);
XWRITE4(sc, oper, XHCI_USBSTS, status);
temp = XREAD4(sc, oper, XHCI_USBSTS);
XWRITE4(sc, oper, XHCI_USBSTS, temp);
temp = XREAD4(sc, oper, XHCI_USBSTS) & XHCI_STS_HCH;
temp = XREAD4(sc, oper, XHCI_USBSTS) & XHCI_STS_HCH;
(XREAD4(sc, oper, XHCI_USBSTS) & XHCI_STS_CNR);
case XHCI_USBSTS:
case XHCI_USBSTS: /* 0x04 */