Re: [PATCH v1 07/10] spi: pxa2xx: Provide num-cs for Sharp PDAs via device properties

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Daniel Mack <daniel@zonque.org>,
	Haojian Zhuang <haojian.zhuang@gmail.com>,
	Robert Jarzmik <robert.jarzmik@free.fr>,
	Russell King <linux@armlinux.org.uk>
Subject: Re: [PATCH v1 07/10] spi: pxa2xx: Provide num-cs for Sharp PDAs via device properties
Date: Tue, 26 Mar 2024 23:20:26 +0200	[thread overview]
Message-ID: <ZgM8GrsaqQb-EjC2@smile.fi.intel.com> (raw)
In-Reply-To: <6f6c96d3-051a-4437-9c95-6b8be7847705@sirena.org.uk>

On Tue, Mar 26, 2024 at 08:26:11PM +0000, Mark Brown wrote:
> On Tue, Mar 26, 2024 at 10:12:12PM +0200, Andy Shevchenko wrote:
> > On Tue, Mar 26, 2024 at 08:02:57PM +0000, Mark Brown wrote:
> 
> > > It is not clear to me that this makes the kernel side better, it just
> > > seems to be rewriting the platform data for the sake of it.  If it was
> > > converting to DT there'd be some stuff from it being DT but this keeps
> > > everything as in kernel as board files, just in a more complex form.
> 
> > Not really. The benefits with swnode conversion are the following:
> 
> > - reducing custom APIs / data types between _shared_ (in a sense of
> >   supporting zillion different platforms) driver and a certain board
> >   file
> 
> > - as an effect of the above, reducing kernel code base, and as the result
> >   make maintenance easier and bug-free for that parts
> 
> I'm more worried about the possibility of breaking things with swnode
> support than I am for board files - with board files you've got a good
> chance of failing to compile if things get messed up, with swnode you
> can typo a property or whatever and silently fail.

I understand that, but here it's consolidated in a single series
and not supposed to be modified in the future, only dropping or
properly converting.

Btw, you may say the same about the all patches that converts to
GPIO lookup tables (one typo in the not-so-often used GPIO line
device ID name), but I don't remember that kind of conversions
got much of objection.

> > - preparing a driver to be ready for any old board file conversion to DT
> >   as it reduces that churn (you won't need to touch the driver code)
> 
> The driver appears to already have DT support (there's a compatible for
> MMP2 in there)?

The MMP2 is using default number of chip select pins.
Also note that my reply is generic (I used 'a driver' form).

-- 
With Best Regards,
Andy Shevchenko