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

[Michel Dänzer]

On 19/05/17 04:35 AM, Felix Kuehling wrote:
> On 17-04-27 05:22 AM, Michel Dänzer wrote:
>> On 27/04/17 05:15 AM, Felix Kuehling wrote:
>>> Hi Michel,
>>>
>>> You said in an earlier email that it doesn't have to be convenient. With
>>> that in mind, I went back to a minimalistic solution that doesn't need
>>> any additional Kconfig options and only uses two module parameters (one
>>> in radeon, one in amdgpu).
>>>
>>> I'm attaching my WIP patches for reference (currently based on
>>> amd-kfd-staging). For an official review I'd rebase them on
>>> amd-staging-4.9, remove the #if-0-ed hack that didn't work out, and add
>>> the same for SI.
>>>
>>> Can everyone can agree that this is good enough?
>> Yes, something like this could be a good first step in the right
>> direction. Some comments:
>>
>> The radeon options should be available regardless of
>> CONFIG_DRM_AMDGPU_CIK/SI, or they won't be useful for amdgpu-pro / other
>> out-of-tree amdgpu builds.
> 
> Hmm, when an amdgpu-pro build is installed on a system with an older
> kernel, radeon won't have the module option at all. Unless the pro-build
> blacklists radeon, or replaces radeon with its own version, it will
> always have to be compiled without CIK support.
> 
> Therefore, I think my patch, meant for upstream, should not consider
> this case.

Obviously, out-of-tree module builds will have to continue doing what
they've been doing so far with kernels without your patch. I'm thinking
about making it easier for them with kernels which do have your patch.
At some point in the future, maybe the support for kernels without your
patch can be dropped entirely.


>> The default at this point should possibly still be for CIK GPUs to be
>> driven by radeon, even if CONFIG_DRM_AMDGPU_CIK is enabled;
> 
> Alex and Christian seem to think otherwise.

FWIW, on my AMD notebook (HP EliteBook 725 G2, Kaveri), suspend/resume
with amdgpu results in a black screen (can reboot blindly); works fine
with radeon.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer