Re: [PATCH] net/mlx5e: Again mutually exclude RX-FCS and RX-port-timestamp

[Tariq Toukan <ttoukan.linux@gmail.com>]

On 10/10/2023 11:52, Paolo Abeni wrote:
> On Tue, 2023-10-10 at 09:31 +0300, Tariq Toukan wrote:
>>
>> On 06/10/2023 8:37, Will Mortensen wrote:
>>> Commit 1e66220948df8 ("net/mlx5e: Update rx ring hw mtu upon each rx-fcs
>>> flag change") seems to have accidentally inverted the logic added in
>>> commit 0bc73ad46a76 ("net/mlx5e: Mutually exclude RX-FCS and
>>> RX-port-timestamp").
>>>
>>> The impact of this is a little unclear since it seems the FCS scattered
>>> with RX-FCS is (usually?) correct regardless.
>>>
>>
>> Thanks for your patch.
>>
>>> Fixes: 1e66220948df8 ("net/mlx5e: Update rx ring hw mtu upon each rx-fcs flag change")
>>> Tested-by: Charlotte Tan <charlotte@extrahop.com>
>>> Reviewed-by: Charlotte Tan <charlotte@extrahop.com>
>>> Cc: Adham Faris <afaris@nvidia.com>
>>> Cc: Aya Levin <ayal@nvidia.com>
>>> Cc: Tariq Toukan <tariqt@nvidia.com>
>>> Cc: Moshe Shemesh <moshe@nvidia.com>
>>> Cc: Saeed Mahameed <saeedm@nvidia.com>
>>> Signed-off-by: Will Mortensen <will@extrahop.com>
>>> ---
>>> For what it's worth, regardless of this change the PCMR register behaves
>>> unexpectedly in our testing on NICs where rx_ts_over_crc_cap is 1 (i.e.
>>> where rx_ts_over_crc is supported), such as ConnectX-7 running firmware
>>> 28.37.1014. For example, fcs_chk is always 0, and rx_ts_over_crc can
>>> never be set to 1 after being set to 0. On ConnectX-5, where
>>> rx_ts_over_crc_cap is 0, fcs_chk behaves as expected.
>>>
>>> We'll probably be opening a support case about that after we test more,
>>> but I mention it here because it makes FCS-related testing confusing.
>>>
>>
>> Please open the case and we'll analyze.
>>
>>>    drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 3 ++-
>>>    1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> index a2ae791538ed..acb40770cf0c 100644
>>> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> @@ -3952,13 +3952,14 @@ static int set_feature_rx_fcs(struct net_device *netdev, bool enable)
>>>    	struct mlx5e_channels *chs = &priv->channels;
>>>    	struct mlx5e_params new_params;
>>>    	int err;
>>> +	bool rx_ts_over_crc = !enable;
>>
>> nit:  Please maintain the reserved Christmas tree.
>>
>>>    
>>>    	mutex_lock(&priv->state_lock);
>>>    
>>>    	new_params = chs->params;
>>>    	new_params.scatter_fcs_en = enable;
>>>    	err = mlx5e_safe_switch_params(priv, &new_params, mlx5e_set_rx_port_ts_wrap,
>>> -				       &new_params.scatter_fcs_en, true);
>>> +				       &rx_ts_over_crc, true);
>>>    	mutex_unlock(&priv->state_lock);
>>>    	return err;
>>>    }
>>
>> Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
> 
> @Tariq: do you prefer we will take this patch directly, or do you
> prefer send it with a later PR?
> 
> Thanks,
> 
> Paolo
> 

Please take it.

Thanks,
Tariq