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

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Message-ID: <1578470.DLzaBp4j3T@vostro.rjw.lan>
Date:	Sun, 27 Sep 2015 16:10:48 +0200
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	linaro-kernel@...ts.linaro.org,
	Viresh Kumar <viresh.kumar@...aro.org>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	"open list:NETWORKING DRIVERS (WIRELESS)" 
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Subject: Re: [PATCH V4 1/2] ACPI / EC: Fix broken 64bit big-endian users of 'global_lock'

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@...nel.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.

Thanks,
Rafael

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