Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 5 Jun 2023 16:11:29 +0200
From:   Herve Codina <herve.codina@bootlin.com>
To:     Andy Shevchenko <andy.shevchenko@gmail.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>
Subject: Re: [PATCH v2 5/9] iio: inkern: Add a helper to query an available
 minimum raw value
Message-ID: <20230605161129.4ac3231b@bootlin.com>
In-Reply-To: <CAHp75Vec3fXT6phqvLGSn0c09USCXXF6ZoE+X1VNJGM6jyf=aQ@mail.gmail.com>
References: <20230523151223.109551-1-herve.codina@bootlin.com>
        <20230523151223.109551-6-herve.codina@bootlin.com>
        <ZHtIdTZbULl6t4RT@surfacebook>
        <20230605094637.7615b689@bootlin.com>
        <CAHp75Vec3fXT6phqvLGSn0c09USCXXF6ZoE+X1VNJGM6jyf=aQ@mail.gmail.com>
Organization: Bootlin
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

Hi Andy,

On Mon, 5 Jun 2023 12:45:24 +0300
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Mon, Jun 5, 2023 at 10:46 AM 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 = vals[--length];  
> > >  
> > > > +                   while (length) {  
> > >
> > >                       while (length--) {
> > >
> > > will do the job and at the same time...
> > >  
> > > > +                           if (vals[--length] < *val)
> > > > +                                   *val = 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 = (len); \
>   typeof(*(array)) __element = (array)[--__len]; \
>   while (__len--) \
>     __element = min(__element, (array)[__len]); \
>   __element; \
> )}
> 
> (it might need more work, but you got the idea)

I will also introduce max_array() and update both iio_channel_read_max()
and iio_channel_read_min() to use these macros.

Will be available in the next series iteration.

Thanks,
Hervé

> 
> > > > +                   }
> > > > +                   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;  
>