Re: [PATCH net-next v7 2/2] net: ti: icssg-prueth: Add ethtool ops for Frame Preemption MAC Merge

[MD Danish Anwar <danishanwar@ti.com>]

Meghana,

On 16/06/26 6:24 pm, Meghana Malladi wrote:
> Hi Jakub,
> 
> On 6/16/26 05:09, Jakub Kicinski wrote:
>> On Mon, 15 Jun 2026 16:10:41 -0700 Jakub Kicinski wrote:
>>>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_stats.h b/drivers/
>>>> net/ethernet/ti/icssg/icssg_stats.h
>>>> index 5ec0b38e0c67..8073deac35c3 100644
>>>> --- a/drivers/net/ethernet/ti/icssg/icssg_stats.h
>>>> +++ b/drivers/net/ethernet/ti/icssg/icssg_stats.h
>>>> @@ -189,6 +187,11 @@ static const struct icssg_pa_stats
>>>> icssg_all_pa_stats[] = {
>>>>       ICSSG_PA_STATS(FW_INF_DROP_PRIOTAGGED),
>>>>       ICSSG_PA_STATS(FW_INF_DROP_NOTAG),
>>>>       ICSSG_PA_STATS(FW_INF_DROP_NOTMEMBER),
>>>> +    ICSSG_PA_STATS(FW_PREEMPT_BAD_FRAG),
>>>> +    ICSSG_PA_STATS(FW_PREEMPT_ASSEMBLY_ERR),
>>>> +    ICSSG_PA_STATS(FW_PREEMPT_FRAG_CNT_TX),
>>>> +    ICSSG_PA_STATS(FW_PREEMPT_ASSEMBLY_OK),
>>>> +    ICSSG_PA_STATS(FW_PREEMPT_FRAG_CNT_RX),
>>>>       ICSSG_PA_STATS(FW_RX_EOF_SHORT_FRMERR),
>>>>       ICSSG_PA_STATS(FW_RX_B0_DROP_EARLY_EOF),
>>>>       ICSSG_PA_STATS(FW_TX_JUMBO_FRM_CUTOFF),
>>>
>>> [Medium]
>>> Are these five new entries duplicating values that already have a
>>> standard uAPI?
>>>
>>> The same five firmware counters are exposed through the new
>>> .get_mm_stats callback as the standardized MAC Merge stats
>>> (MACMergeFrameAssOkCount, MACMergeFrameAssErrorCount,
>>> MACMergeFragCountRx,
>>> MACMergeFragCountTx, MACMergeFrameSmdErrorCount in struct
>>> ethtool_mm_stats), and adding them to icssg_all_pa_stats[] also
>>> publishes them via emac_get_strings() / emac_get_ethtool_stats() as
>>> ethtool -S strings.
>>>
>>> Documentation/networking/statistics.rst describes ethtool -S as the
>>> private-driver-stats interface; counters that have a standard uAPI are
>>> expected to flow only through that uAPI.
>>>
>>> Could the firmware-register lookup table used by emac_get_stat_by_name()
>>> be separated from the ethtool -S string table, so the new preemption
>>> counters feed get_mm_stats without also showing up under ethtool -S?
>>
>> This -- not sure about the other complaints but this one looks legit.
> 
> I agree that this is legit, but right now there is no other place holder
> other than pa stats to put the mac merge firmware counters. I believe

You can put a boolean is_standard_stats. Only those where
is_standard_stats=false will be populated via ethtool. Others will be
populated via the standard interface.

Look at icssg_miig_stats for reference.

> the effort needs to go in re-structuring the hardware and firmware stats
> implementation to address this issue.
> 

-- 
Thanks and Regards,
Danish