REG_PEX_ERR_DR
err_reg = bus_space_read_4(sc->sc_bst, sc->sc_bsh, REG_PEX_ERR_DR);
bus_space_write_4(sc->sc_bst, sc->sc_bsh, REG_PEX_ERR_DR, clear_reg);
bus_space_write_4(sc->sc_bst, sc->sc_bsh, REG_PEX_ERR_DR,