Re: [PATCH net-next 5/5] ionic: Add .get_fec_stats ethtool handler

[Eric Joyner <eric.joyner@amd.com>]

On 5/5/2026 6:54 AM, Vadim Fedorenko wrote:
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> 
> On 01/05/2026 04:15, Eric Joyner wrote:
>> Several FEC error statistics being collected can be reported in a
>> dedicated ethtool callback for FEC errors, so implement the handler that
>> does so. This includes 802.3ck FEC histogram data that some newer
>> hardware collects.
>>
>> Assisted-by: Claude:claude-4.6-sonnet
>> Signed-off-by: Eric Joyner <eric.joyner@amd.com>
>> ---
>>   .../ethernet/pensando/ionic/ionic_ethtool.c   | 51 +++++++++++++++++++
>>   1 file changed, 51 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c b/drivers/
>> net/ethernet/pensando/ionic/ionic_ethtool.c
>> index 78a802eb159f..fe1f753b6115 100644
>> --- a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
>> +++ b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
>> @@ -418,6 +418,56 @@ static int ionic_get_fecparam(struct net_device *netdev,
>>       return 0;
>>   }
>>
>> +static const struct ethtool_fec_hist_range ionic_fec_ranges[] = {
>> +     { 0, 0},
>> +     { 1, 1},
>> +     { 2, 2},
>> +     { 3, 3},
>> +     { 4, 4},
>> +     { 5, 5},
>> +     { 6, 6},
>> +     { 7, 7},
>> +     { 8, 8},
>> +     { 9, 9},
>> +     { 10, 10},
>> +     { 11, 11},
>> +     { 12, 12},
>> +     { 13, 13},
>> +     { 14, 14},
>> +     { 15, 15},
>> +     { 0, 0},
>> +};
>> +
>> +static void
>> +ionic_fill_fec_hist(const struct ionic_port_extra_stats *extra_stats,
>> +                 struct ethtool_fec_hist *hist)
>> +{
>> +     int i;
>> +
>> +     hist->ranges = ionic_fec_ranges;
>> +     for (i = 0; i < ETHTOOL_FEC_HIST_MAX - 1; i++)
>> +             hist->values[i].sum = extra_stats->fec_codeword_error_bin[i];
>> +}
> 
> ETHTOOL_FEC_HIST_MAX = 17, you defined 16 bins, but iterating over 15 of
> them. Looks like bin {15, 15} will be lost in stats.
> 
> 

This looks correct to me -- (ETHTOOL_FEC_HIST_MAX - 1) = 16, so starting with
i=0, it'll iterate through the 16 bins and ignore the 17th end marker bin. Bin
15 does get included and gets its sum set.

- Eric