Re: [PATCH net,v2, 1/3] net: mana: Fix TX CQE error handling

[Shradha Gupta]

On Fri, Sep 29, 2023 at 01:42:25PM -0700, Haiyang Zhang wrote:
> For an unknown TX CQE error type (probably from a newer hardware),
> still free the SKB, update the queue tail, etc., otherwise the
> accounting will be wrong.
> 
> Also, TX errors can be triggered by injecting corrupted packets, so
> replace the WARN_ONCE to ratelimited error logging.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
> Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index 4a16ebff3d1d..5cdcf7561b38 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -1317,19 +1317,23 @@ static void mana_poll_tx_cq(struct mana_cq *cq)
>  		case CQE_TX_VPORT_IDX_OUT_OF_RANGE:
>  		case CQE_TX_VPORT_DISABLED:
>  		case CQE_TX_VLAN_TAGGING_VIOLATION:
> -			WARN_ONCE(1, "TX: CQE error %d: ignored.\n",
> -				  cqe_oob->cqe_hdr.cqe_type);
> +			if (net_ratelimit())
> +				netdev_err(ndev, "TX: CQE error %d\n",
> +					   cqe_oob->cqe_hdr.cqe_type);
> +
>  			apc->eth_stats.tx_cqe_err++;
>  			break;
>  
>  		default:
> -			/* If the CQE type is unexpected, log an error, assert,
> -			 * and go through the error path.
> +			/* If the CQE type is unknown, log an error,
> +			 * and still free the SKB, update tail, etc.
>  			 */
> -			WARN_ONCE(1, "TX: Unexpected CQE type %d: HW BUG?\n",
> -				  cqe_oob->cqe_hdr.cqe_type);
> +			if (net_ratelimit())
> +				netdev_err(ndev, "TX: unknown CQE type %d\n",
> +					   cqe_oob->cqe_hdr.cqe_type);
> +
>  			apc->eth_stats.tx_cqe_unknown_type++;
> -			return;
> +			break;
>  		}
>  
>  		if (WARN_ON_ONCE(txq->gdma_txq_id != completions[i].wq_num))
> -- 
> 2.25.1
Reviewed-by: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>