smi_write_locked
err = smi_write_locked(sc, addr, data, sleep);
err = smi_write_locked(sc, addr, newv, sleep);
err = smi_write_locked(sc, RTL8366_PACR, RTL8366_PACR_READ, sleep);
err = smi_write_locked(sc, RTL8366_PHYREG(phy, 0, reg), 0, sleep);
err = smi_write_locked(sc, RTL8366_PACR, RTL8366_PACR_WRITE, sleep);
err = smi_write_locked(sc, RTL8366_PHYREG(phy, 0, reg), data, sleep);