On Fri, May 31, 2019 at 09:12:03PM +0300, Vladimir Oltean wrote:

It won't work unless I make changes to dsa_switch_rcv.

Or to the tagging code.

Right now taggers can only return a pointer to the skb, or NULL, case
in which DSA will free it.

The tagger can re-write the skb.  Why not reform it into a PTP frame?
This clever trick is what the phyter does in hardware.  See dp83640.c.

Thanks,
Richard