Re: [Intel-wired-lan] [RFC PATCH v5] ethtool: add FEC bins histogramm report

[Carolina Jubran <cjubran@nvidia.com>]

On 18/08/2025 21:35, Vadim Fedorenko wrote:
> On 18/08/2025 19:17, Carolina Jubran wrote:
>>
>>
>> On 15/08/2025 16:27, Vadim Fedorenko wrote:
>>> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
>>> index de5bd76a400ca..6c0dc6ae080a8 100644
>>> --- a/include/linux/ethtool.h
>>> +++ b/include/linux/ethtool.h
>>> @@ -492,7 +492,25 @@ struct ethtool_pause_stats {
>>>   };
>>>   #define ETHTOOL_MAX_LANES    8
>>> +#define ETHTOOL_FEC_HIST_MAX    18
>>
>> Could you clarify why it is set to 18?
>> AFAIU IEEE 802.3ck/df define 16 bins.
> 
> Yeah, the standard defines 16 bins, but this value came out of the
> discussion with Gal and Yael because the hardware supports more bins,
> I believe, in RDMA mode
> 

currently I believe those are internal modes that expose 19 on our 
hardware. Therefore, I think 16 is sufficient and we can easily extend 
in the future.

>>> diff --git a/net/ethtool/fec.c b/net/ethtool/fec.c
>>> index e7d3f2c352a34..9313bd17544fd 100644
>>> --- a/net/ethtool/fec.c
>>> +++ b/net/ethtool/fec.c
>>> @@ -17,6 +17,7 @@ struct fec_reply_data {
>>>           u64 stats[1 + ETHTOOL_MAX_LANES];
>>>           u8 cnt;
>>>       } corr, uncorr, corr_bits;
>>> +    struct ethtool_fec_hist fec_stat_hist;
>>>   };
>>>   #define FEC_REPDATA(__reply_base) \
>>> @@ -113,7 +114,11 @@ static int fec_prepare_data(const struct 
>>> ethnl_req_info *req_base,
>>>           struct ethtool_fec_stats stats;
>>>           ethtool_stats_init((u64 *)&stats, sizeof(stats) / 8);
>>> -        dev->ethtool_ops->get_fec_stats(dev, &stats);
>>> +        ethtool_stats_init((u64 *)data->fec_stat_hist.values,
>>> +                   ETHTOOL_MAX_LANES *
>> this should be ETHTOOL_FEC_HIST_MAX since we’re initializing the 
>> histogram bins array.
> 
> Yes, you're right, I'll change it in the next version