Subject: Re: [PATCH net-next 3/3] net/mlx4_en: Add tx queue maxrate support

From: Sergei Shtylyov <[email-masked]>
Date: Wed, 11 Mar 2015 18:44:21 +0300

Hello.

On 3/11/2015 4:14 PM, Or Gerlitz wrote:

> Add ndo_set_tx_maxrate support.

> To support per tx queue maxrate limit, we use the update-qp firmware
> command to do run-time rate setting for the qp that serves this tx ring.
>
> Signed-off-by: Or Gerlitz <[email-masked]>
> Signed-off-by: Ido Shamay <[email-masked]>
> ---
>   drivers/net/ethernet/mellanox/mlx4/en_netdev.c |   33 ++++++++++++++++++++++++
>   1 files changed, 33 insertions(+), 0 deletions(-)

> diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> index c59ed92..2a58d2a 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> @@ -2379,6 +2379,37 @@ static netdev_features_t mlx4_en_features_check(struct sk_buff *skb,
>   }
>   #endif
>
> +int mlx4_en_set_tx_maxrate(struct net_device *dev, int queue_index, u32 maxrate)
> +{
> +	struct mlx4_en_priv *priv = netdev_priv(dev);
> +	struct mlx4_en_tx_ring *tx_ring = priv->tx_ring[queue_index];
> +	struct mlx4_update_qp_params params;
> +	int err;
> +
> +	if (!(priv->mdev->dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_QP_RATE_LIMIT)) {
> +		err = -EOPNOTSUPP;
> +		goto out;

    I would have just used *return*...

> +	}
> +
> +	/* rate provided to us in Mbs, check if it fits into 12 bits, if not use Gbs */
> +	if ((maxrate >> 12)) {

    Double parens make not sense.

[...]
> +	err = mlx4_update_qp(priv->mdev->dev, tx_ring->qpn, MLX4_UPDATE_QP_RATE_LIMIT,
> +			     &params);
> +
> +out:
> +	return err;
> +}
> +
>   static const struct net_device_ops mlx4_netdev_ops = {
>   	.ndo_open		= mlx4_en_open,
>   	.ndo_stop		= mlx4_en_close,
[...]

WBR, Sergei