[PATCH] accel: work around DRM_ACCEL dependencies

[Arnd Bergmann]

On Fri, Jan 27, 2023, at 11:17, Stanislaw Gruszka wrote:
> On Fri, Jan 27, 2023 at 10:36:20AM +0100, Arnd Bergmann wrote:

>> I think it will be necessary to establish a link hierarchy between drm.ko
>> and drm_accel.ko to avoid circular dependencies like this, but until then
>> the only way that both can be used is to have both subsystems built into
>> the kernel. Enforce this using a Kconfig dependency.
>
> Hmm, it was discussed a bit before and conclusion was that accel will be
> compiled in drm.ko to avoid circular dependencies. There should be
> no drm_accel.ko module.

Ok, got it. This does not sounds like a great solution as it ties
the two modules closer together than most users want, but it should
work as long as we control the dependencies for the individual drivers.

>> diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig
>> index 834863902e16..dd18d3b2028c 100644
>> --- a/drivers/accel/Kconfig
>> +++ b/drivers/accel/Kconfig
>> @@ -8,7 +8,7 @@
>>  #
>>  menuconfig DRM_ACCEL
>>  	bool "Compute Acceleration Framework"
>> -	depends on DRM
>> +	depends on DRM=y
>
> Would making ivpu Kconfig:
>
> depends on DRM
> select DRM_ACCEL
>
> solve the problem and still allow to drm to be build as module ? 

Right, that should work, I'll send a v2 patch to add an "if DRM"
around the entire drivers/accel/Kconfig file, which should have the
effect.

     Arnd