ARC_RD_OUTB_DOORBELL_CLR
arc_write(sc, ARC_RD_OUTB_DOORBELL_CLR,
arc_write(sc, ARC_RD_OUTB_DOORBELL_CLR, ob_doorbell);
arc_write(sc, ARC_RD_OUTB_DOORBELL_CLR, reg);
arc_write(sc, ARC_RD_OUTB_DOORBELL_CLR, ARC_RD_I2D_MSG_CMD_DONE_CLR);