[PATCH] drm: Harmonize CIK ASIC support in radeon and amdgpu (v2)

[Felix Kuehling]

On 17-04-11 12:01 AM, Michel Dänzer wrote:
> One issue with this per-driver enable_cik option is that if the user
> only enables it in the driver where it's disabled by default, without
> also disabling it in the driver where it's enabled by default, it's back
> to the current situation where both drivers try to use the same GPUs,
> and it's up to chance which one actually gets to.
>
> That's why I was thinking about also having a shared command line option
> respected by both drivers, e.g. amd_cik_driver=amdgpu/radeon . That
> would be the preferred way to choose the driver at runtime.

The shared option could not be in either amdgpu or radeon. Otherwise
we'd create a cross-dependency between the drivers. It would have to be
in drm, I guess?

> Note that the per-driver enable_cik option will still be needed to be
> able to override the kernel command line when manually loading the drivers.

Why? I could make the shared option writable in
/sys/module/drm/parameters/amd_cik_driver so you can change it before
loading the module.

Regards,
  Felix

>
> Maybe there's a better way to handle both cases that I haven't thought of.
>
>