Re: [PATCH v1 03/10] v4l: platform: Add Renesas CEU driver

From: Sakari Ailus <sakari.ailus@iki.fi>
To: jacopo mondi <jacopo@jmondi.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>,
	laurent.pinchart@ideasonboard.com, magnus.damm@gmail.com,
	geert@glider.be, mchehab@kernel.org, hverkuil@xs4all.nl,
	linux-renesas-soc@vger.kernel.org, linux-media@vger.kernel.org,
	linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 03/10] v4l: platform: Add Renesas CEU driver
Date: Sat, 25 Nov 2017 17:56:14 +0200	[thread overview]
Message-ID: <20171125155613.ebblr7hdr6irs2h7@valkosipuli.retiisi.org.uk> (raw)
In-Reply-To: <20171117093355.GE4668@w540>

On Fri, Nov 17, 2017 at 10:33:55AM +0100, jacopo mondi wrote:
> Hi Sakari!
> 
> On Fri, Nov 17, 2017 at 02:36:51AM +0200, Sakari Ailus wrote:
> > Hi Jacopo,
> >
> > On Wed, Nov 15, 2017 at 03:25:11PM +0100, jacopo mondi wrote:
> > > Hi Sakari,
> > >    thanks for review!
> >
> > You're welcome!
> >
> > > On Wed, Nov 15, 2017 at 02:45:51PM +0200, Sakari Ailus wrote:
> > > > Hi Jacopo,
> > > >
> > > > Could you remove the original driver and send the patch using git
> > > > send-email -C ? That way a single patch would address converting it to a
> > > > proper V4L2 driver as well as move it to the correct location. The changes
> > > > would be easier to review that way since then, well, it'd be easier to see
> > > > the changes. :-)
> > >
> > > Actually I prefer not to remove the existing driver at the moment. See
> > > the cover letter for reasons why not to do so right now...
> >
> > So it's about testing mostly? Does someone (possibly you) have those boards
> > to test? I'd like to see this patchset to remove that last remaining SoC
> > camera bridge driver. :-)
> 
> Well, we agreed that for most of those platforms, compile testing it
> would be enough (let's believe in "if it compiles, it works"). I
> personally don't have access to those boards, and frankly I'm not even
> sure there are many of them around these days (I guess most of them
> are not even produced anymore).
> 
> >
> > >
> > > Also, there's not that much code from the old driver in here, surely
> > > less than the default 50% -C and -M options of 'git format-patch' use
> > > as a threshold for detecting copies iirc..
> >
> > Oh, if that's so, then makes sense to review it as a new driver.
> 
> thanks :)
> 
> >
> > >
> > > > The same goes for the two V4L2 SoC camera sensor / video decoder drivers at
> > > > the end of the set.
> > > >
> > >
> > > Also in this case I prefer not to remove existing code, as long as
> > > there are platforms using it..
> >
> > Couldn't they use this driver instead?
> 
> Oh, they will eventually, I hope :)
> 
> I would like to make sure we're all on the same page with this. My
> preference would be:
> 
> 1) Have renesas-ceu.c driver merged with Migo-R ported to use this new
> driver as an 'example'.
> 2) Do not remove any of the existing soc_camera code at this point
> 3) Port all other 4 SH users of sh_mobile_ceu_camera to use the now
> merged renesas-ceu driver
> 4) Remove sh_mobile_ceu_camera and soc_camera sensor drivers whose
> only users were those 4 SH boards
> 5) Remove soc_camera completely. For my understanding there are some
> PXA platforms still using soc_camera provided utilities somewhere.
> Hans knows better, but we can discuss this once we'll get there.

The first point here is basically done by this patchset and your intent
would be to proceed with the rest, right?

The above seems good; what I wanted to say was that I'd like to avoid
ending up in a permanent situation where some hardware works with the new
driver and some will continue to use the old one.

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi