On Thu, Jun 30, 2022 at 03:46:06PM +0200, Christian Marangi wrote:

Move qca8k driver to qca dir in preparation for code split and
introduction of ipq4019 switch based on qca8k.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
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Posting this as a RFC to discuss the problems of such change.

This is needed as in the next future the qca8k driver will be split
to a common code. This needs to be done as the ipq4019 is based on qca8k
but will have some additional configuration thing and other phylink
handling so it will require different setup function. Aside from these
difference almost all the regs are the same of qca8k.

For this reason keeping the driver in the generic dsa dir would create
some caos and I think it would be better to move it the dedicated qca
dir.

This will for sure creates some problems with backporting patch.

So the question is... Is this change acceptable or we are cursed to
keeping this driver in the generic dsa directory?

Additional bonus question, since the ethernet part still requires some
time to get merged, wonder if it's possible to send the code split with
qca8k as the only user (currently) and later just add the relevant
ipq4019 changes.

(this ideally is to prepare stuff and not send a big scary series when
it's time to send ipq4019 changes)

I think we discussed this before. You can make the driver migration but
you need to be willing to manually backport bug fixes if/when the stable
team reports that backporting to a certain kernel failed. It has been
done before, see commit a9770eac511a ("net: mdio: Move MDIO drivers into
a new subdirectory") as an example. I think "git cherry-pick" has magic
to detect file movement, while "git am" doesn't. Here I'm not 100%
certain which command is used to backport to stable. If it's by cherry
picking it shouldn't even require manual intervention.