From: Eric Dumazet <eduma...@google.com>
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 <eduma...@google.com>
Cc: Willem de Bruijn <will...@google.com>
Reviewed-by: Eran Ben Elisha <era...@mellanox.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Jiri Slaby <jsl...@suse.cz>
---
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
