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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Mon, 5 Jun 2023 12:45:24 +0300
Message-ID: <CAHp75Vec3fXT6phqvLGSn0c09USCXXF6ZoE+X1VNJGM6jyf=aQ@mail.gmail.com>
Subject: Re: [PATCH v2 5/9] iio: inkern: Add a helper to query an available
 minimum raw value
To:     Herve Codina <herve.codina@bootlin.com>
Cc:     Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
        alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>
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On Mon, Jun 5, 2023 at 10:46=E2=80=AFAM Herve Codina <herve.codina@bootlin.=
com> wrote:
> On Sat, 3 Jun 2023 17:04:37 +0300
> andy.shevchenko@gmail.com wrote:
> > Tue, May 23, 2023 at 05:12:19PM +0200, Herve Codina kirjoitti:

...

> > > +           case IIO_VAL_INT:
> > > +                   *val =3D vals[--length];
> >
> > > +                   while (length) {
> >
> >                       while (length--) {
> >
> > will do the job and at the same time...
> >
> > > +                           if (vals[--length] < *val)
> > > +                                   *val =3D vals[length];
> >
> > ...this construction becomes less confusing (easier to parse).
>
> Indeed, I will change in the next iteration.

And looking into above line, this whole construction I would prefer to
have a macro in minmax.h like

#define min_array(array, len) \
{( \
  typeof(len) __len =3D (len); \
  typeof(*(array)) __element =3D (array)[--__len]; \
  while (__len--) \
    __element =3D min(__element, (array)[__len]); \
  __element; \
)}

(it might need more work, but you got the idea)

> > > +                   }
> > > +                   break;

...

> > > +           default:
> > > +                   /* FIXME: learn about min for other iio values */
> >
> > I believe in a final version this comment won't be here.
>
> We have the same FIXME comment in the iio_channel_read_max() function I
> copied to create this iio_channel_read_min() and, to be honest, I
> don't really know how to handle these other cases.
>
> In this series, I would prefer to keep this FIXME.

I see, Jonathan needs to be involved here then.

> > > +                   return -EINVAL;

--=20
With Best Regards,
Andy Shevchenko