Re: [PATCH net-next 02/11] net: dsa: tag_rzn1_a5psw: Add RZ/T2H ETHSW tag protocol and register ethsw tag driver

Lad, Prabhakar
2025-11-21T20:29:32Z

Hi Vladimir,

Thank you for the review.

On Fri, Nov 21, 2025 at 7:27 PM Vladimir Oltean <olteanv@gmail.com> wrote:
>
> On Fri, Nov 21, 2025 at 11:35:28AM +0000, Prabhakar wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > Add an explicit tag protocol for the RZ/T2H ETHSW and register a separate
> > ethsw tag driver so the existing A5PSW tag implementation can be reused
> > for RZ/T2H without code duplication.
> >
> > The ETHSW IP on RZ/T2H shares substantial commonality with the A5PSW IP on
> > RZ/N1, and the current tag driver does not touch the register fields that
> > differ between the two blocks.
>
> Tagging protocol drivers are specifically written to not deal with
> register fields. I would like a clarification that this is a phrasing
> mistake and you mean the packet header fields that differ between the
> ETHSW and the A5PSW tag format.
>
Unlike the other drivers, tagging drivers don't have compatible
strings to match against. For the ETHSW IP, the current driver is
reused as-is. My intention with the comment was simply to point out
that, if an issue ever arises that requires us to split the paths, we
can future-proof things by using DSA_TAG_PROTO_* identifiers.

Cheers,
Prabhakar