From: Dekel Peled <dekelp@mellanox.com>
Date: Thu, 28 Feb 2019 15:20:30 +0000 (+0200)
Subject: net/mlx5: fix sync when handling Tx completions
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=fd350d3c9a13b5ebcb41741870c3f09b6920033f;p=dpdk.git

net/mlx5: fix sync when handling Tx completions

Function mlx5_tx_complete() reads completion entry information
from Tx queue.
For some processors not having strongly-ordered memory model,
there has to be a memory barrier between reading the entry index
and the entry fields, in order to guarantee data is valid.

Fixes: 54d3fe948dba ("net/mlx5: poll completion queue once per a call")
Cc: stable@dpdk.org

Signed-off-by: Dekel Peled <dekelp@mellanox.com>
Acked-by: Shahaf Shuler <shahafs@mellanox.com>
---

diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index c0e1adf140..53115dde3d 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -568,6 +568,7 @@ mlx5_tx_complete(struct mlx5_txq_data *txq)
 	}
 #endif /* NDEBUG */
 	++cq_ci;
+	rte_cio_rmb();
 	txq->wqe_pi = rte_be_to_cpu_16(cqe->wqe_counter);
 	ctrl = (volatile struct mlx5_wqe_ctrl *)
 		tx_mlx5_wqe(txq, txq->wqe_pi);