IGC_SWSM_SWESMBI
wr32(IGC_SWSM, swsm | IGC_SWSM_SWESMBI);
if (rd32(IGC_SWSM) & IGC_SWSM_SWESMBI)
swsm &= ~(IGC_SWSM_SMBI | IGC_SWSM_SWESMBI);