Re: [PATCH V4 1/2] ACPI / EC: Fix broken 64bit big-endian users of 'global_lock'

Arnd Bergmann
2015-09-28T08:24:58Z

On Sunday 27 September 2015 16:10:48 Rafael J. Wysocki wrote:
> On Saturday, September 26, 2015 09:33:56 PM Arnd Bergmann wrote:
> > On Saturday 26 September 2015 11:40:00 Viresh Kumar wrote:
> > > On 25 September 2015 at 15:19, Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > So if you allow something like debugfs to update your structure, how
> > > > do you make sure there is the proper locking?
> > >
> > > Not really sure at all.. Isn't there some debugfs locking that will
> > > jump in, to avoid updation of fields to the same device?
> >
> > No, if you need any locking to access variable, you cannot use the
> > simple debugfs helpers but have to provide your own functions.
> >
> > > >> Anyway, that problem isn't here for sure as its between two
> > > >> unsigned-longs. So, should I just move it to bool and resend ?
> > > >
> > > > I guess it might be more convenient to fold this into the other patch,
> > > > because we seem to be splitting hairs here.
> > >
> > > I can and that's what I did. But then Arnd asked me to separate it
> > > out. I can fold it back if that's what you want.
> >
> > It still makes sense to keep it separate I think, the patch is clearly
> > different from the other parts.
>
> I just don't see much point in going from unsigned long to u32 and then
> from 32 to bool if we can go directly to bool in one go.

It's only important to keep the 34-file multi-subsystem trivial cleanup
that doesn't change any functionality separate from the bugfix. If you
like to avoid patching one of the files twice, the alternative would
be to first change the API for all other instances from u32 to bool
and leave ACPI alone, and then do the second patch that changes ACPI
from long to bool.

Arnd

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