Re: [PATCH net-next v3 0/3] net: dsa: mv88e6xxx: various hwstamp fixes

[Jakub Kicinski <kuba@kernel.org>]

On Sun, 19 Jul 2026 15:30:52 +1000 Luke Howard wrote:
> Three fixes for improving the reliably of hardware timestamp acquisition
> on Marvell switches. In our tests this eliminated missed timestamps in
> ptp4l, whilst also preserving PTP event and general message ordering on
> switches that support embedded timestamps.

Do you know if there's any precedent in the existing upstream drivers
for overriding the reserved bytes? It's not normal for devices to modify
the ingress frames. Perhaps there's some precedent, but if not I think
we should gate this (eg with a devlink param?)

Andrew, do you have any opinion? Or perhaps Richard?

> Note: squashing the two embedded timestamp patches into a single commit
> may be desirable.

I think it would be great to invert the order. Revamp the locking as
patch 2 then add the new feature as patch 3.