Message-ID: <6c81ef5a8407d9bb782dfbc9365a4c0658b667ca.camel@perches.com>
Subject: Re: [PATCH v6 2/2] Driver for ON Semi AR0521 camera sensor
From:   Joe Perches <joe@perches.com>
To:     Jacopo Mondi <jacopo@jmondi.org>
Cc:     Krzysztof =?UTF-8?Q?Ha=C5=82asa?= <khalasa@piap.pl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>, devicetree@vger.kernel.org,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Sakari Ailus <sakari.ailus@iki.fi>
Date:   Fri, 24 Dec 2021 04:30:36 -0800
In-Reply-To: <20211224092226.vmqkmybpx4zodezt@uno.localdomain>
References: <m3ee63hkuu.fsf@t19.piap.pl> <m35yrfhkaf.fsf@t19.piap.pl>
         <cee1bbe6c8dda1c79ba19f7bbf68fc1d74558cae.camel@perches.com>
         <20211223184856.v34ecibwzepahsju@uno.localdomain>
         <02c71d9fe95f72c5aa5a01adadda8fb7e756fae1.camel@perches.com>
         <20211224092226.vmqkmybpx4zodezt@uno.localdomain>
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On Fri, 2021-12-24 at 10:22 +0100, Jacopo Mondi wrote:
> Hi Joe

hi again.

> On Thu, Dec 23, 2021 at 12:13:10PM -0800, Joe Perches wrote:
> > On Thu, 2021-12-23 at 19:48 +0100, Jacopo Mondi wrote:
> > > The media subsystem requires to validate patches with
> > > 
> > >         ./scripts/checkpatch.pl --strict --max-line-length=80
> > > 
> > > We longly debated this and I believe it's now generally accepted to go
> > > over 80 when it makes sense, but not regularly span to 120 cols like
> > > in the previous version.
> > 
> > Where is this documented and do you have a link to the debate?
> 
> It's in the subsystem maintainer profile
> Documentation/driver-api/media/maintainer-entry-profile.rst
> 
> Where of course some exceptions are listed but it's anyway enforced
> that "efforts should be made towards staying within 80
> characters per line"
> 
>     - on strings, as they shouldn't be broken due to line length limits;
>     - when a function or variable name need to have a big identifier name,
>       which keeps hard to honor the 80 columns limit;
>     - on arithmetic expressions, when breaking lines makes them harder to
>       read;
>     - when they avoid a line to end with an open parenthesis or an open
>       bracket.
> 
> The debate I mentioned was specifically on the previous version of the
> driver where me and Krzysztof shown quite different understanding of
> coding style requirements.
> https://patchwork.linuxtv.org/project/linux-media/patch/m3fstfoexa.fsf@t19.piap.pl/

Thanks for that.

> That lead me to submit this
> https://patchwork.linuxtv.org/project/linux-media/patch/20211013092005.14268-1-jacopo@jmondi.org/

That too.

FWIW, I believe using more than 100 columns or so makes it more
difficult to track quickly and efficiently to the next line.
Reading with multiple visual saccades on a single line is slow.

And IMO:

o reverse xmas tree declarations is quite a poor style requirement
o single line c99 // comments should be encouraged/preferred
o identifiers longer than 20 characters or so should be discouraged