From: Eric Dumazet <edumazet@xxxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit fc96256c906362e845d848d0f6a6354450059e81 ] When multiple skb are TX-completed in a row, we might incorrectly keep a timestamp of a prior skb and cause extra work. Fixes: ec693d47010e8 ("net/mlx4_en: Add HW timestamping (TS) support") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Willem de Bruijn <willemb@xxxxxxxxxx> Reviewed-by: Eran Ben Elisha <eranbe@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index 0698c82d6ff1..3d3cd0f1adf8 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -343,7 +343,6 @@ static void mlx4_en_process_tx_cq(struct net_device *dev, struct mlx4_en_cq *cq) u32 packets = 0; u32 bytes = 0; int factor = priv->cqe_factor; - u64 timestamp = 0; if (!priv->port_up) return; @@ -375,9 +374,12 @@ static void mlx4_en_process_tx_cq(struct net_device *dev, struct mlx4_en_cq *cq) new_index = be16_to_cpu(cqe->wqe_index) & size_mask; do { + u64 timestamp = 0; + txbbs_skipped += ring->last_nr_txbb; ring_index = (ring_index + ring->last_nr_txbb) & size_mask; - if (ring->tx_info[ring_index].ts_requested) + + if (unlikely(ring->tx_info[ring_index].ts_requested)) timestamp = mlx4_en_get_cqe_ts(cqe); /* free next descriptor */ -- 2.8.2 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html