[Linux-kernel-mentees] [PATCH] cs5535: use BIT() macro for defining bit-flags

Amol Surati suratiamol at gmail.com
Mon Jul 8 08:57:35 UTC 2019


On Mon, Jul 08, 2019 at 11:02:29AM +0300, Andy Shevchenko wrote:
> On Sun, Jul 7, 2019 at 2:30 PM Amol Surati <suratiamol at gmail.com> wrote:
> >
> > The BIT() macro is available for defining the required bit-flags.
> 
> Shouldn't bits.h be added?
> 
> > Since it operates on an unsigned value and expands to an unsigned result,
> > using it, instead of an expression like (1 << x), also fixes the problem
> > of shifting a signed 32-bit value by 31 bits. (e.g. 1 << 31. See
> > CS5536_GPIOM7_PME_FLAG and CS5536_GPIOM7_PME_EN).
> 
> What problem?
> You need to describe that (UB by the standard, though gcc works fine,
> I never heard it utilizes such).

Yes. I will send a new version. I also missed including
<linux/bitops.h>, although the compilation with the default
configuration of my distro still succeeds without it, by chance.

Thank you,
-amol

> 
> -- 
> With Best Regards,
> Andy Shevchenko


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