Re: drivers/iio/adc/xilinx-ams.c:1195:21: error: unused variable 'ams'

[Geert Uytterhoeven]

Hi Jonathan.

On Mon, Feb 14, 2022 at 8:17 PM Jonathan Cameron
<Jonathan.Cameron@xxxxxxxxxx> wrote:
> On Mon, 14 Feb 2022 22:47:14 +0800
> kernel test robot <lkp@xxxxxxxxx> wrote:
>
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   754e0b0e35608ed5206d6a67a791563c631cec07
> > commit: d5c70627a79455154f5f636096abe6fe57510605 iio: adc: Add Xilinx AMS driver
> > date:   8 weeks ago
> > config: sh-allmodconfig (https://download.01.org/0day-ci/archive/20220214/202202142203.4ofqbic9-lkp@xxxxxxxxx/config)
> > compiler: sh4-linux-gcc (GCC) 11.2.0
> > reproduce (this is a W=1 build):
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d5c70627a79455154f5f636096abe6fe57510605
> >         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> >         git fetch --no-tags linus master
> >         git checkout d5c70627a79455154f5f636096abe6fe57510605
> >         # save the config file to linux build tree
> >         mkdir build_dir
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=sh SHELL=/bin/bash drivers/iio/adc/ drivers/net/ethernet/freescale/
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> I'm very tempted to say won't fix on this at least not in the IIO code.
>
> The issue I think is the stub for iounmap on sh with no MMU not using the argument because it's

Indeed.

> defined as a while loop rather than as an empty static inline function which is what we'd
> get it it wasn't defined at all (AFAICT).

We would get that only if <asm-generic/io.h> would be included...

> If anyone wants to take this on, my guess is drop
> https://elixir.bootlin.com/linux/latest/source/arch/sh/include/asm/io.h#L274
> and see if everything still works and the warning goes away.

Nope:

    error: implicit declaration of function ‘iounmap’

> +CC linux-sh for inputs.

Thanks, I'll post a fix.

> > All errors (new ones prefixed by >>):
> >
> >    drivers/iio/adc/xilinx-ams.c: In function 'ams_iounmap_ps':
> > >> drivers/iio/adc/xilinx-ams.c:1195:21: error: unused variable 'ams' [-Werror=unused-variable]
> >     1195 |         struct ams *ams = data;
> >          |                     ^~~
> >    drivers/iio/adc/xilinx-ams.c: In function 'ams_iounmap_pl':
> >    drivers/iio/adc/xilinx-ams.c:1202:21: error: unused variable 'ams' [-Werror=unused-variable]
> >     1202 |         struct ams *ams = data;
> >          |                     ^~~
> >    cc1: all warnings being treated as errors

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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