Re: [PATCH v6 2/2] media: i2c: Add GC08A3 image sensor driver

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Kieran Bingham <kieran.bingham@ideasonboard.com>,
	Jonathan Cameron <jic23@kernel.org>
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Subject: Re: [PATCH v6 2/2] media: i2c: Add GC08A3 image sensor driver
Date: Wed, 28 Feb 2024 20:06:14 +0200	[thread overview]
Message-ID: <CAHp75Ve=gRhRMN-3JyEZ3EX3oU72buGhGTx6jukgwOzO=KRjNA@mail.gmail.com> (raw)
In-Reply-To: <170914163823.252503.15921889437591940623@ping.linuxembedded.co.uk>

On Wed, Feb 28, 2024 at 7:34 PM Kieran Bingham
<kieran.bingham@ideasonboard.com> wrote:
> Quoting Andy Shevchenko (2024-02-28 17:17:12)
> > On Wed, Feb 28, 2024 at 2:03 PM sakari.ailus@linux.intel.com
> > <sakari.ailus@linux.intel.com> wrote:
> > > On Wed, Feb 28, 2024 at 11:22:13AM +0200, Andy Shevchenko wrote:
> > > > > Another, I also reviewed some other sensor driver code(such as
> > > > > gc0a08/gc2145 and imx/ov), they are all the same.
> > > >
> > > > They are also problematic. So what?
> > >
> > > The situation is the same in a large number of drivers, also outside the
> > > media tree. It's also not trivial to figure out which header should be
> > > included and it tends to be that if it compiles without warnings,
> > > developers won't bother trying to figure out what should still be changed.
> >
> > I spent about 20 minutes reading the code. Yes, for inexperienced
> > developers it can take 3x longer, but still, much longer time was
> > spent on writing that code to begin with. So, the headers are a part
> > of the evolution of the code. And now it's pure technical debt with no
> > excuses to not fulfill.
> >
> > TL;DR: It's (rightfully) assumed that the developer *knows* their code.
> >
> > > I wonder if this could be automated by using the C preprocessor and a
> > > small Perl script. :-)
> >
> > There is a Google project coming from Clang people or so, but I have
> > no idea of the state of affairs.
>
> I've used iwyu (include-what-you-use) successfully on libcamera. But I
> don't know how this would translate to working on the kernel, with a
> more complex build system.

Jonathan tried that once. It needs to be heavily tweaked to be used in
the kernel project.

> But indeed, tooling already exists [0] to do these checks, and is packaged
> in distros [1]
>
> [0] https://include-what-you-use.org/
> [1] https://manpages.ubuntu.com/manpages/focal/man1/iwyu_tool.1.html

-- 
With Best Regards,
Andy Shevchenko