[dpdk-stable] [PATCH 1/2] net/mlx5: fix Rx CQ doorbell synchronization on aarch64

[Phil Yang]

The Rx completion queue doorbell field needs to be updated after
the last CQE decompressed. For the weaker memory model processors,
the compiler barrier is not sufficient to guarantee the order of
these operations, so use the coherent I/O memory barrier to make
sure these fields are updated in order.

Fixes: 570acdb1da8a ("net/mlx5: add vectorized Rx/Tx burst for ARM")
Cc: stable at dpdk.org

Suggested-by: Gavin Hu <gavin.hu at arm.com>
Signed-off-by: Phil Yang <phil.yang at arm.com>
Reviewed-by: Gavin Hu <gavin.hu at arm.com>
---
 drivers/net/mlx5/mlx5_rxtx_vec_neon.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx_vec_neon.h b/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
index 9930286..e914d01 100644
--- a/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
+++ b/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
@@ -727,7 +727,7 @@ rxq_burst_v(struct mlx5_rxq_data *rxq, struct rte_mbuf **pkts, uint16_t pkts_n,
 			rxq->decompressed -= n;
 		}
 	}
-	rte_compiler_barrier();
+	rte_cio_wmb();
 	*rxq->cq_db = rte_cpu_to_be_32(rxq->cq_ci);
 	return rcvd_pkt;
 }
-- 
2.7.4