BUS_DMASYNC_POSTWRITE
BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
ahd_sync_sglist(ahd, scb, BUS_DMASYNC_POSTWRITE);
BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
ahc_sync_sglist(ahc, scb, BUS_DMASYNC_POSTWRITE);