[PATCH v2 13/13] ARM: s3c24xx: camif: include header with prototypes and unify declaration

[Krzysztof Kozlowski]

On Wed, Aug 12, 2020 at 05:58:52PM +0200, Sylwester Nawrocki wrote:
> On 12.08.2020 15:31, Krzysztof Kozlowski wrote:
> > On Wed, Aug 12, 2020 at 03:11:41PM +0200, Sylwester Nawrocki wrote:
> >> On 12.08.2020 13:28, Arnd Bergmann wrote:
> >>> On Wed, Aug 12, 2020 at 12:46 PM Sylwester Nawrocki
> >>> <s.nawrocki at samsung.com> wrote:
> >>>> On 12.08.2020 11:14, Arnd Bergmann wrote:
> 
> >>> I see two board files (and no DT) instantiate the camif device:
> >>> NexVision Nexcoder 2440 and the FriendlyARM mini2440.
> >>>
> >>> Can you say whether the camif on those would actually work
> >>> at all without your patch? If not, we know that there are no
> >>> users of that driver and could either drop it completely or move
> >>> it to staging for a release or two.
> >>
> >> Without additional patches the camif will not work, the driver 
> >> needs an instance of struct s3c_camif_plat_data which specifies
> >> what image sensor is attached.
> >>
> >> I think we can drop the driver, together with the s3c_camif_device
> >> platform device definitions. It can always be added again if anyone
> >> ever needs it or converts the platform to DT.
> > 
> > Since the header was in /include/media I assumed there might be some
> > user-space tools using it. But if it is not the case, I'll drop the code
> > then.
> 
> That's a kernel internal header, only for board files, it should really 
> have been added to include/linux/platform_data.
>   
> >> IMO all non-DT code in arch/arm/mach-s3c24xx is a candidate for
> >> removal, it just adds to the maintenance effort and I seriously
> >> doubt there are now any users of it.
> > 
> > That is quite tricky... I really do not know whether there are any real
> > world users of S3C24xx and S3C64xx platforms. Evalkits are mostly not
> > available for buying so I do not expect new designs. However still
> > existing ones might be somewhere... Few years ago, back in Samsung, I
> > mentioned removing them. That time I think Marek or you Sylwester, said
> > that there are industrial applications using S3C24xx. I believe, why
> > not. The trouble is - how to find such users? How to get in touch for
> > testing or at least for bug reports if something is broken?
> 
> I believe if there any such applications of the S3C24XX SoCs still existing 
> somewhere their long term support doesn't include updating to new kernels. 
> I used to keep a running S3C2440 SoC based board just for the purpose of
> testing patches touching the common code, but I stopped it, I think it is
> not worth to waste time and health on it any more. For example support for 
> the OSELAS.BSP-Pengutronix-Mini2440 BSP I used for tests ended 5 years ago
> [1].
> 
> > Or even more important - is it worth to spend effort and time on this?
> > If there is no single production system using recent Linux kernel, the
> > answer should be negative...
> 
> I suspect nobody cares about that code (non-DT s3c24xx) any more for other
> than sentimental reasons.

I'll start then with S3C camif driver. :) I guess
drivers/media/platform/s3c-camif/ still should be left?

Best regards,
Krzysztof