ATL2_ISR
AT_WRITE_4(sc, ATL2_ISR, 0xffffffff);
error = ((AT_READ_4(sc, ATL2_ISR) & ISR_PHY_LINKDOWN) != 0);
AT_WRITE_4(sc, ATL2_ISR, 0x3fffffff);
AT_WRITE_4(sc, ATL2_ISR, 0);
status = AT_READ_4(sc, ATL2_ISR);
AT_WRITE_4(sc, ATL2_ISR, status | ISR_DIS_INT);
AT_WRITE_4(sc, ATL2_ISR, 0);