Re: [PATCH] iio: st_pressure_spi: Add missing entries SPI to device ID table

From: Jonathan Cameron <jic23@kernel.org>
To: Denis CIOCCA <denis.ciocca@st.com>
Cc: Mark Brown <broonie@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	"linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>
Subject: Re: [PATCH] iio: st_pressure_spi: Add missing entries SPI to device ID table
Date: Thu, 7 Oct 2021 16:27:16 +0100	[thread overview]
Message-ID: <20211007162716.0abd5937@jic23-huawei> (raw)
In-Reply-To: <AM8PR10MB4801DB5353ADA0656510E920EDB19@AM8PR10MB4801.EURPRD10.PROD.OUTLOOK.COM>

On Thu, 7 Oct 2021 00:47:56 +0000
Denis CIOCCA <denis.ciocca@st.com> wrote:

> Hello Mark,
> 
> > -----Original Message-----
> > From: Mark Brown <broonie@kernel.org>
> > Sent: Friday, October 1, 2021 5:20 AM
> > To: Denis CIOCCA <denis.ciocca@st.com>
> > Cc: Jonathan Cameron <jic23@kernel.org>; Lars-Peter Clausen
> > <lars@metafoo.de>; linux-iio@vger.kernel.org
> > Subject: Re: [PATCH] iio: st_pressure_spi: Add missing entries SPI to device
> > ID table
> > 
> > On Thu, Sep 30, 2021 at 06:35:23PM +0000, Denis CIOCCA wrote:
> >   
> > > I am not very familiar with how much the kernel would like to keep  
> > 'probing id' consistent. I perfectly understand the value of doing this
> > (maintain ID compatibility) but I also see increase confusion in maintaining
> > half in a way and half in another.
> > 
> > The goal is not to maintain compatibility, the goal is to be able to
> > load the driver as a module on DT systems.  For historical reasons SPI
> > uses the platform device IDs to load modules bound with DT, if there is
> > no platform ID for a DT ID then userspace won't be able to find and load
> > the module.  
> 
> Ok now it is clear. I wasn't aware of that.
> In this case it is good to me (I didn't do any testing).

Applied to the fixes-togreg branch of iio.git. I haven't explicitly marked
it for stable but it may make sense to backport at somepoint.

Thanks,

Jonathan

> 
> >   
> > > I personally think that we should drop the '-press' thing for all the devices  
> > since they all are single-chip (meaning that the name used identify
> > univocally that is a pressure sensor).
> > 
> > The DT bindings are an ABI, you can't really remove compatibles only
> > deprecate them.  
> 
> Yeah I guessed this was the case.
> 
> >   
> > > If you think that compatibility is more important here, I think the patch is  
> > fine but this should be done in the i2c part as well so that it's at least
> > congruent withing the driver.
> > 
> > I2C doesn't have this issue with modaliases so it's not an issue there.  
> 
> Clear.
> 
> > 
> > Please fix your mail client to word wrap within paragraphs at something
> > substantially less than 80 columns.  Doing this makes your messages much
> > easier to read and reply to.  