Re: [PATCH] comedi: Fix driver module dependencies since HAS_IOPORT changes

[Arnd Bergmann]

On Mon, Sep 4, 2023, at 08:01, Ian Abbott wrote:
> On 04/09/2023 12:23, Niklas Schnelle wrote:
>> On Mon, 2023-09-04 at 11:10 +0100, Ian Abbott wrote:
>
> Thanks for the confirmation.  Will it be safe to assume that anything 
> that selects ISA will also select HAS_IOPORT?  That is trivially the 
> case for arch/{alpha,arm,x86}; arch/mips explicitly selects HAS_IOPORT 
> if ISA is selected; arch/powerpc explicitly selects HAS_IOPORT if PCI is 
> selected and it is only possible to configure ISA if PPC_CHRP is 
> configured which selects FORCE_PCI and therefore selects PCI and 
> therefore selects HAS_IOPORT; arch/um does not select HAS_IOPORT and 
> although it has a 'config ISA', nothing appears to select it.  None of 
> the remaining arch/* have 'select ISA'.

Yes, I think that will always be a safe assumption, ISA without port I/O
is just not a sensible configuration. A few of the later ISA devices use
PCI style memory mapped I/O, but I can't think of any driver that doesn't
also require port I/O, and you wouldn't find ISA slots in a system that
lacks support for port I/O.

      Arnd