On Sat, Apr 23, 2016 at 9:35 PM, Eric Dumazet <eric.duma...@gmail.com> wrote:
> From: Eric Dumazet <eduma...@google.com>
>
> 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>
> Willem de Bruijn <will...@google.com>
Eric, was that supposed to be Reported-by: or Signed-off-by: ...
FWIW, Dave, I wanted to use the opportunity and comment that this week
many of us gonna be on Passover vacation, so response rate should be
lower than usual
> 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 c0d7b7296236..a386f047c1af 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
> @@ -405,7 +405,6 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev,
> u32 packets = 0;
> u32 bytes = 0;
> int factor = priv->cqe_factor;
> - u64 timestamp = 0;
> int done = 0;
> int budget = priv->tx_work_limit;
> u32 last_nr_txbb;
> @@ -445,9 +444,12 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev,
> new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
>
> do {
> + u64 timestamp = 0;
> +
> txbbs_skipped += last_nr_txbb;
> ring_index = (ring_index + 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 */
>
>
