Re: [linux-next:master] BUILD REGRESSION 736ee37e2e8eed7fe48d0a37ee5a709514d478b3

[Geert Uytterhoeven <geert@linux-m68k.org>]

On Fri, May 20, 2022 at 2:40 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> On Thu, May 19, 2022 at 8:48 AM Guenter Roeck <linux@roeck-us.net> wrote:
> > On 5/18/22 17:55, kernel test robot wrote:
> > > tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > branch HEAD: 736ee37e2e8eed7fe48d0a37ee5a709514d478b3  Add linux-next specific files for 20220518
> > >
> > > Error/Warning reports:
> > >
> > > https://lore.kernel.org/linux-mm/202204291924.vTGZmerI-lkp@intel.com
> > > https://lore.kernel.org/linux-mm/202205041248.WgCwPcEV-lkp@intel.com
> > > https://lore.kernel.org/linux-mm/202205122113.uLKzd3SZ-lkp@intel.com
> > > https://lore.kernel.org/linux-mm/202205172344.3GFeaum1-lkp@intel.com
> > > https://lore.kernel.org/linux-mm/202205190527.o9wVEvHI-lkp@intel.com
> > >
> > > Error/Warning: (recently discovered and may have been fixed)
> > >
> > [ .. ]
> > > drivers/hwmon/nct6775-platform.c:199:9: sparse:    unsigned char
> > > drivers/hwmon/nct6775-platform.c:199:9: sparse:    void
> >
> > This is getting tiresome. Every driver using outb() on m68k will
> > experience that "problem". As far as I can see, it is caused by
> >
> > #define out_8(addr,b) (void)((*(__force volatile u8 *) (unsigned long)(addr)) = (b))
> >
> > in arch/m68k/include/asm/raw_io.h. I have no idea what the
> > "(void)" is for,
>
> The "(void)" makes sure there is no return value.
> Which matters if the result of a function returning void is propagated
> to another function returning void.

Which, FTR, sparse also doesn't like:

    error: return expression in void function

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds