On Fri, Oct 11, 2024 at 09:59:46AM +0000, Arnd Bergmann wrote:
> 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.
Do you have any examples of that in the kernel?
> 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.
Yes, but it's not what your code does.
--
With Best Regards,
Andy Shevchenko
