Re: [GIT PULL 1/2] asm-generic: rework PCI I/O space access

From: John Garry
Date: Fri Dec 17 2021 - 11:30:45 EST


On 17/12/2021 15:55, Arnd Bergmann wrote:
> If you have a better way of finding the affected drivers,
> that would be great.

Assuming arm64 should select HAS_IOPORT, I am talking about f71805f as
an example. According to that patch, this driver additionally depends on
HAS_IOPORT; however I would rather arm64, like powerpc, should not allow
that driver to be built at all.
Agreed, I missed these when I looked through the HAS_IOPORT users,
that's why I suggested to split up that part of the patch per subsystem
so they can be inspected more carefully.

ok

>
> 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