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

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

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