Re: [PATCH] media: staging: drop omap4iss

[Andreas Kemnade <andreas@kemnade.info>]

Am Tue, 19 Nov 2024 09:02:22 +0200
schrieb Laurent Pinchart <laurent.pinchart@ideasonboard.com>:

> Hi Andreas,
> 
> On Mon, Nov 18, 2024 at 08:00:25PM +0100, Andreas Kemnade wrote:
> > Am Mon, 2 Sep 2024 10:42:31 +0200 schrieb Hans Verkuil :
> >   
> > > The omap4 camera driver has seen no progress since forever, and
> > > now OMAP4 support has also been dropped from u-boot (1). So it is
> > > time to retire this driver.  
> > 
> > Argumenting with OMAP4 support in U-Boot is silly. That indicates that
> > there is no movement in keeping u-boot uptodate. Bootloader
> > development/updating is more risky especially if not done by the vendor,
> > good chances to brick something. And the bootloader might need
> > signing. So that argument is done nothing.
> > 
> > Better arguments would be to check if someone has something cooking and
> > feels not comfortable yet to climb Mount Upstream.
> > 
> > A good place to ask would be the omap platform
> > list: linux-omap@vger.kernel.org
> > 
> > I get still devicetrees for omap4 devices to review. So there is some
> > activity with omap4. If you look at postmarketOS you see also some
> > activity.
> > 
> > And also someone ported the driver to devicetree support:
> > https://github.com/iridia-ulb/meta-builderbot/blob/master/recipes-kernel/linux/linux-stable-4.16/0008-omap4iss-Fix-multiple-bugs-and-use-device-tree.patch
> > 
> > So the situation is not that simple. I am still evaluating it because I
> > myself have a device with omap4 and camera.  
> 
> Have you tested the camera recently ? The omap4iss driver has been
> unmaintained in mainline for a very, very long time, and I would be
> surprised if it worked.
> 
No, I have not tested it. I only have a bitrot out of tree driver for my
camera which was probably never used with omap. Vendor system seems to
handle camera via the m3 processor in a closed-source firmware blob. So
what is the overall picture:

Which omap4 devices have cameras? What is the status of the sensor
driver? Known working/Mainline/Out-of-tree/none? Datasheet for
sensor available?
The question is whether omap4iss can be tested together with a
known-working camera sensor driver. That would make things a lot easier.

BT200 has a camera without mainline sensor driver.
Droid4 has also a camera. What is the status of the sensor driver?
What about the samsung-espresso tablets? And the xyboards?

Pandaboard camera module? If have a pandaboard I use for reference, but
no camera there.

> If someone is interested in taking over maintainership and improving the
> driver to get it out of drivers/staging/ to drivers/media/, the removal
> can certainly be reverted. drivers/staging/ is not a place where drivers
> are left to bitrot, it's meant for active development of code not fully
> ready for mainline yet.
> 
I guess the way to start is to revert the remove and then update the
above-mentioned devicetree support patch. I have no feeling how complex
that whole task would be.

Regards,
Andreas