MLX5_RCV_DBR
qp->db.db[MLX5_RCV_DBR] = 0;
rq->mpwqe.wq.db = &rq->mpwqe.wq.db[MLX5_RCV_DBR];
rq->wqe.wq.db = &rq->wqe.wq.db[MLX5_RCV_DBR];
wq->rq.db = &wq_ctrl->db.db[MLX5_RCV_DBR];
qp->rq.db = &qp->db.db[MLX5_RCV_DBR];