XHCI_IMOD
xhci_rt_write_4(sc, XHCI_IMOD(0), XHCI_IMOD_DEFAULT_LP);
xhci_rt_write_4(sc, XHCI_IMOD(0), 0);
xhci_rt_read_4(sc, XHCI_IMOD(0)));
sc->sc_regs.imod0 = xhci_rt_read_4(sc, XHCI_IMOD(0));
xhci_rt_write_4(sc, XHCI_IMOD(0), sc->sc_regs.imod0);