There is really no need to recompute the static parts of the tags on
each skb. It would mean moving some knowledge of the tagging format to
the driver. But that boundary is pretty artificial for
mv88e6xxx. tag_dsa has no use outside of mv88e6xxx, and mv88e6xxx does
not work with any other tagger. I suppose you could even move the whole
tagger to drivers/net/dsa/mv88e6xxx/?

What do you think?

Andrew?

We have resisted this before.

What information do you actually need to share between the tagger and
the driver? Both tag_lan9303.c and tag_ocelot_8021q.c do reference
their switch driver data structures, so some sharing is allowed. But
please try to keep the surface areas down.

       Andrew