Re: [GIT PULL for v7.4] media updates

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Tue, Oct 27, 2026 at 12:56:56AM +0100, Mauro Carvalho Chehab wrote:
> On Mon, 26 Oct 2026 08:53:07 -1000 Linus Torvalds wrote:
> 
> > On Mon, 26 Oct 2026 at 08:25, Sakari Ailus <sakari.ailus@linux.intel.com> wrote:
> > >
> > > The patch in question puts camera sensors and related chips in line with
> > > how the rest of the drivers are selected elsewhere.  
> > 
> > .. and other places could probably be improved too, I agree.
> > 
> > But this made things *worse*. Much worse.
> > 
> > The thing is, at least hide them behind some "embedded camera options"
> > that in turn is hidden behind "EXPERT" or something like that.
> > 
> > Don't make *normal* people who build their own kernels have to see or know.
> > 
> > Let's say that you have a laptop or something that actually uses one
> > of these sensors for a webcam, then it STILL does not help to ask a
> > user
> > 
> >  "Do you want a driver for the Analog Devices ADV7170 video encoder"
> > 
> > Because (a) that chip legacy and likely not in any laptop anyway and
> > (b) even if it was, no laptop user is going to *know* that.
> > 
> > See what I'm saying? You literally make things worse. Don't do that.
> > You're making the kernel Kconfig script ask insane questions. They are
> > insane because you cannot reasonably expect people to actually know
> > the answer to the questions.
> > 
> > In other words: don't ask questions that you know the user cannot answer.
> > 
> > There was a REASON why those menus were hidden.
> 
> I agree with Linus on that. You're basically rolling back a feature
> that simplifies a lot the life for normal users: let Kconfig choose
> options that only a media expert can answer.
> 
> Now, I understand why it is tempting to do that to help with IPU
> support: camera sensors can now be easily interchangeable on new 
> Intel hardware.
> 
> If you look on some drivers from the old days, like bttv, saa7134
> and cx88, they had similar problems, but they still do support
> autoselect mode.
> 
> For instance, drivers/media/tuners/Kconfig has this:
> 
>    config MEDIA_TUNER
>         tristate
>         depends on (MEDIA_ANALOG_TV_SUPPORT || MEDIA_DIGITAL_TV_SUPPORT || MEDIA_RADIO_SUPPORT || MEDIA_SDR_SUPPORT) && I2C
>         default y
>         select MEDIA_TUNER_XC2028 if MEDIA_SUBDRV_AUTOSELECT
>         select MEDIA_TUNER_XC5000 if MEDIA_SUBDRV_AUTOSELECT
>         select MEDIA_TUNER_XC4000 if MEDIA_SUBDRV_AUTOSELECT
>         select MEDIA_TUNER_MT20XX if MEDIA_SUBDRV_AUTOSELECT
>         select MEDIA_TUNER_TDA8290 if MEDIA_SUBDRV_AUTOSELECT
>         select MEDIA_TUNER_TEA5761 if MEDIA_SUBDRV_AUTOSELECT && MEDIA_RADIO_SUPPORT
>         select MEDIA_TUNER_TEA5767 if MEDIA_SUBDRV_AUTOSELECT && MEDIA_RADIO_SUPPORT
>         select MEDIA_TUNER_SIMPLE if MEDIA_SUBDRV_AUTOSELECT
>         select MEDIA_TUNER_TDA9887 if MEDIA_SUBDRV_AUTOSELECT
>         select MEDIA_TUNER_MC44S803 if MEDIA_SUBDRV_AUTOSELECT
> 
> which is meant to support the most popular I2C tuners.
> 
> In the specific case of IPU (and atomisp, once moved out of staging),
> the right solution would be to have something similar to it, e.g.
> something like:
> 
> 	config VIDEO_INTEL_IPU6
> 	select VIDEO_OV2680 if MEDIA_SUBDRV_AUTOSELECT
> 	select VIDEO_OV2685 if MEDIA_SUBDRV_AUTOSELECT
> 	...
> 	
> for each sensor that might be possible to be used there. Another
> alternative would be to do it the reverse way, e.g.:
> 	
> 	config VIDEO_OV2680
> 		default MEDIA_SUBDRV_AUTOSELECT && VIDEO_INTEL_IPU6
> 
> or, maybe even better:
> 
> 	# Make setup easier by identifying PC MC-based drivers on a single place
> 	config MEDIA_SENSOR_AUTOSELECT
> 	depends on VIDEO_INTEL_IPU6
> 	default y
> 
> 	config VIDEO_OV2680
> 	default MEDIA_SENSOR_AUTOSELECT
> 
> Placing MEDIA_SENSOR_AUTOSELECT on sensor drivers. We may need
> similar code also for other I2C drivers that could be used on IPU.

You're forgetting that this affects not only Intel-based machines with
raw sensors, but a lot of Arm laptops too. We would end up selecting a
vast majority of sensor drivers unconditionally. If we want to go that
route, a single option to select all camera sensor drivers would be
simpler.

-- 
Regards,

Laurent Pinchart