Re: [PATCH net-next v3 1/4] ethtool: add FEC bins histogram report

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 18 Sep 2025 11:53:53 +0100 Vadim Fedorenko wrote:
> On 18/09/2025 01:41, Jakub Kicinski wrote:
> > On Tue, 16 Sep 2025 19:12:54 +0000 Vadim Fedorenko wrote:  
> >> IEEE 802.3ck-2022 defines counters for FEC bins and 802.3df-2024
> >> clarifies it a bit further. Implement reporting interface through as
> >> addition to FEC stats available in ethtool.
> >> diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
> >> index 7a7594713f1f..de5008266884 100644
> >> --- a/Documentation/netlink/specs/ethtool.yaml
> >> +++ b/Documentation/netlink/specs/ethtool.yaml
> >> @@ -1219,6 +1219,23 @@ attribute-sets:
> >>           name: udp-ports
> >>           type: nest
> >>           nested-attributes: tunnel-udp
> >> +  -
> >> +    name: fec-hist
> >> +    attr-cnt-name: __ethtool-a-fec-hist-cnt  
> > 
> > s/__/--/  
> 
> That will bring strong inconsistency in schema. All other attributes
> have counter attribute with __ in the beginning:
> 
>      name: fec-stat
>      attr-cnt-name: __ethtool-a-fec-stat-cnt
> 
>      name: stats-grp
>      attr-cnt-name: __ethtool-a-stats-grp-cnt
> 
>      name: stats
>      attr-cnt-name: __ethtool-a-stats-cnt

I know.

> >>   static void
> >> -nsim_get_fec_stats(struct net_device *dev, struct ethtool_fec_stats *fec_stats)
> >> +nsim_get_fec_stats(struct net_device *dev, struct ethtool_fec_stats *fec_stats,
> >> +		   struct ethtool_fec_hist *hist)
> >>   {
> >> +	struct ethtool_fec_hist_value *values = hist->values;
> >> +
> >> +	hist->ranges = netdevsim_fec_ranges;
> >> +
> >>   	fec_stats->corrected_blocks.total = 123;
> >>   	fec_stats->uncorrectable_blocks.total = 4;
> >> +
> >> +	values[0].bin_value = 445;  
> > 
> > Bin 0 had per lane breakdown, can't core add up the lanes for the
> > driver?  
> 
> Like it's done for blocks counter? Should we force drivers to keep 'sum'
> value equal to ETHTOOL_STAT_NOT_SET when they provide per-lane values?

No preference, but if it is NOT_SET we should add it up.