T_XUSB_CFG_ARU_SMI_INTR_REG
irv = bus_space_read_4(bst, fpcih, T_XUSB_CFG_ARU_SMI_INTR_REG);
bus_space_write_4(bst, fpcih, T_XUSB_CFG_ARU_SMI_INTR_REG, irv);