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Date:   Tue, 25 Jan 2022 15:17:44 +0200
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Liam Beguin <liambeguin@gmail.com>
Cc:     Jonathan Cameron <jic23@kernel.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Andreas Kemnade <andreas@kemnade.info>,
        linux-arm-msm@vger.kernel.org, linux-iio@vger.kernel.org,
        linux-kernel@vger.kernel.org, Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Peter Rosin <peda@axentia.se>
Subject: Re: [PATCH v2 5/5] iio: afe: iio-rescale: Re-use generic struct
 s32_fract
Message-ID: <Ye/4eJ/RhlWF7q70@smile.fi.intel.com>
References: <20220110193104.75225-1-andriy.shevchenko@linux.intel.com>
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 <20220115185203.567780e8@jic23-huawei>
 <Ye7DSAN4gdhXfEUs@smile.fi.intel.com>
 <Ye8Z6dS5cCji9LNQ@shaak>
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On Mon, Jan 24, 2022 at 04:28:09PM -0500, Liam Beguin wrote:
> On Mon, Jan 24, 2022 at 05:18:32PM +0200, Andy Shevchenko wrote:
> > On Sat, Jan 15, 2022 at 06:52:03PM +0000, Jonathan Cameron wrote:
> > > On Mon, 10 Jan 2022 21:31:04 +0200
> > > Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> > > 
> > > > Instead of custom data type re-use generic struct s32_fract.
> > > > No changes intended.
> > > > 
> > > > The new member is put to be the first one to avoid additional
> > > > pointer arithmetic. Besides that one may switch to use fract
> > > > member to perform container_of(), which will be no-op in this
> > > > case, to get struct rescale.
> > > > 
> > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > > 
> > > I'm not totally sold on this series showing there is a strong case for
> > > these macros so interested to hear what others think.
> > 
> > So far no news :-)
> 
> Like I mentioned briefly in the other thread[1], I don't really see the
> advantage for the AFE driver given that it's almost just like renaming
> the parameters.

I tend to disagree, perhaps I wasn't so clear in my points.

The change reveals that the layering can be improved. In OOP
the object A which is inherited (or encapsulated as we see here)
allows to clearly get what kind of data the methods are operating
with / on. As you may see the two functions and the method
declaration appears to have interest only in the fraction data
for rescaling. The cleanup I consider helpful in the terms
of layering and OOP.

> For the other drivers affected by the change, it drops the definition of
> the structure which is nice. So overall, it's a plus IMO :-)

Thanks!

> [1] https://lore.kernel.org/linux-iio/20220108205319.2046348-1-liambeguin@gmail.com/

-- 
With Best Regards,
Andy Shevchenko