IB/mlx5: Make sure doorbell record is visible before doorbell

Put a wmb() to make sure the doorbell record is visible to the HCA before we hit doorbell. Signed-off-by: Eli Cohen <eli@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
hardkernel · Jan 23, 2014 · ada388f · ada388f
1 parent 042b9ad
commit ada388f
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
@@ -2251,6 +2251,10 @@ int mlx5_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
 
 		qp->db.db[MLX5_SND_DBR] = cpu_to_be32(qp->sq.cur_post);
 
+		/* Make sure doorbell record is visible to the HCA before
+		 * we hit doorbell */
+		wmb();
+
 		if (bf->need_lock)
 			spin_lock(&bf->lock);