Re: [PATCH v2 2/3] acpi: allow building without CONFIG_HAS_IOPORT

[Arnd Bergmann]

On Fri, Oct 11, 2024, at 09:53, Andy Shevchenko wrote:
> On Fri, Oct 11, 2024 at 06:18:18AM +0000, Arnd Bergmann wrote:
>
> ...
>
>> +	if (!IS_ENABLED(CONFIG_HAS_IOPORT)) {
>> +		*value = BIT_MASK(width);
>> +		return AE_NOT_IMPLEMENTED;
>
> Perhaps it has already been discussed, but why do we need to file value with
> semi-garbage when we know it's invalid anyway?

It's not strictly necessary, just precaution for possible callers
that use the resulting data without checking the error code.

The all-ones data is what an x86 PC would see when an I/O
port is read that is not connected to any device.

     Arnd