Re: [PATCH v6 2/2] Driver for ON Semi AR0521 camera sensor

From: Joe Perches
Date: Fri Dec 24 2021 - 07:32:12 EST


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@xxxxxxxxxxx/

Thanks for that.

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

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