Re: [PATCH net] net: tsnep: fix timestamping with a stacked DSA driver

[Gerhard Engleder <gerhard@engleder-embedded.com>]

On 13.05.25 22:06, Vladimir Oltean wrote:
> On Tue, May 13, 2025 at 08:34:17PM +0200, Gerhard Engleder wrote:
>> On 12.05.25 23:09, Vladimir Oltean wrote:
>>> On Mon, May 12, 2025 at 10:07:52PM +0200, Gerhard Engleder wrote:
>>>> On 12.05.25 15:24, Vladimir Oltean wrote:
>>>>> This driver seems susceptible to a form of the bug explained in commit
>>>>> c26a2c2ddc01 ("gianfar: Fix TX timestamping with a stacked DSA driver")
>>>>> and in Documentation/networking/timestamping.rst section "Other caveats
>>>>> for MAC drivers", specifically it timestamps any skb which has
>>>>> SKBTX_HW_TSTAMP, and does not consider adapter->hwtstamp_config.tx_type.
>>>>
>>>> Is it necessary in general to check adapter->hwtstamp_config.tx_type for
>>>> HWTSTAMP_TX_ON or only to fix this bug?
>>>
>>> I'll start with the problem description and work my way towards an answer.
>>
>> (...)
>>
>>>> I can take over this patch and test it when I understand more clearly
>>>> what needs to be done.
>>>>
>>>> Gerhard
>>>
>>> It would be great if you could take over this patch. After the net ->
>>> net-next merge I can then submit the ndo_hwtstamp_get()/ndo_hwtstamp_set()
>>> conversion patch for tsnep, the one which initially prompted me to look
>>> into how this driver uses the provided configuration.
>>
>> I will post a new patch version in the next days. You can send me the
>> ndo_hwtstamp_get()/ndo_hwtstamp_set() conversion patch for testing. I
>> have it on my list, but nothing done so far, so I feel responsible
>> for that too.
>>
>> Gerhard
> 
> See attached. It applies on top of this patch ("do_tstamp" is present in
> the context).

I tested the ndo_hwtstamp_get()/ndo_hwtstamp_set() conversion patch
successfully on top of the timestamping fix patch. Thank you for the
patch!

Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Tested-by: Gerhard Engleder <gerhard@engleder-embedded.com>