Subject: Re: [PATCH net-next v2 2/2] net: mana: Add standard counter rx_missed_errors

From: Jakub Kicinski <[email-masked]>
Date: Fri, 31 Oct 2025 16:17:23 -0700

On Wed, 29 Oct 2025 03:37:52 -0700 Erni Sri Satya Vennela wrote:
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index 009e869ef296..48df44889f05 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -494,6 +494,11 @@ static void mana_get_stats64(struct net_device *ndev,
>  
>  	netdev_stats_to_stats64(st, &ndev->stats);
>  
> +	if (apc->ac->hwc_timeout_occurred)
> +		netdev_warn_once(ndev, "HWC timeout occurred\n");

I don't think there's much value in this print.

> +#define MANA_GF_STATS_PERIOD (2 * HZ)
> +
> +static void mana_gf_stats_work_handler(struct work_struct *work)
> +{
> +	struct mana_context *ac =
> +		container_of(to_delayed_work(work), struct mana_context, gf_stats_work);
> +	int err;
> +
> +	err = mana_query_gf_stats(ac);
> +	if (err == -ETIMEDOUT) {
> +		/* HWC timeout detected - reset stats and stop rescheduling */
> +		ac->hwc_timeout_occurred = true;
> +		memset(&ac->hc_stats, 0, sizeof(ac->hc_stats));

Not sure I've seen another device using this approach but I can't
really tell what's the best strategy. The device is unusable if it
can't provide stats..

> +		return;
> +	}
> +	queue_delayed_work(ac->gf_stats_wq, &ac->gf_stats_work, MANA_GF_STATS_PERIOD);
> +}
> +
>  int mana_probe(struct gdma_dev *gd, bool resuming)
>  {
>  	struct gdma_context *gc = gd->gdma_context;
> @@ -3478,6 +3503,15 @@ int mana_probe(struct gdma_dev *gd, bool resuming)
>  	}
>  
>  	err = add_adev(gd, "eth");
> +	ac->gf_stats_wq = create_singlethread_workqueue("mana_gf_stats");

Why are you creating a workqueue? You can use system queues.

> +	queue_delayed_work(ac->gf_stats_wq, &ac->gf_stats_work, MANA_GF_STATS_PERIOD);

ls wrap long lines at 80 chars.

> diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> index 3dfd96146424..99e811208683 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
> @@ -213,8 +213,6 @@ static void mana_get_ethtool_stats(struct net_device *ndev,
>  
>  	if (!apc->port_is_up)
>  		return;
> -	/* we call mana function to update stats from GDMA */
> -	mana_query_gf_stats(apc->ac);

Why delete this? We can get fresh stats for the user in this context.