On Tue, 2021-12-21 at 16:48 +0000, John Garry wrote:

On 20/12/2021 09:27, Niklas Schnelle wrote:

quoted

quoted

  > My feeling is that in this case we want some other dependency, e.g. a
  > new CONFIG_LPC. It should actually be possible to use this driver on
  > any machine with an LPC bus, which would by definition be the primary
  > I/O space, so it should be possible to load it on Arm64.

You did suggest HARDCODED_IOPORT earlier in this thread, and the
definition/premise there seemed sensible to me.

Anyway it seems practical to make all these changes in a single series,
so need a way forward as Niklas has no such changes for this additional
kconfig option.

As a start, may I suggest we at least have Niklas' patch committed to a
dev branch based on -next or latest mainline release for further analysis?

Thanks,
John

My plan would be to split the patch up into more manageable pieces as
suggested by Arnd plus of course fixes like the missing ARM select. As
Arnd suggested I'll split the HAS_IOPORT additions into the initial
introduction plus arch selects and then the HAS_IOPORT dependencies per
subsytem. I think these per subsystem dependency patches then would be
a great place to find drivers which should have a different dependency
be it on LPC or a newly introduced HARDCODED_IOPORT. The thing is we
can find and check HAS_IOPORT dependencies easily but it's hard to find
HARDCODED_IOPORT so I think the lattter should be a refinement of the
former. It can of course still go in as a single series. I'll
definitely make the next iteration available as a git branch.

I'll do an audit for what would require HARDCODED_IOPORT to understand 
the scope while you can continue the work on your current path.

Thanks,
john

Sounds good, I'm open to adding such a config option given a clear
enough picture of what drivers it would affect. Meanwhile I've made
some progress splitting things up. I still need to do a bit more
testing and refining of comments before sending an RFC but if you're
curious you can check out the 'has_ioport' branch on my GitHub here:

https://github.com/niklas88/linux.git  (still figuring out if/how I can
get a proper git.kernel.org branch/repository).

Thanks,
Niklas