[amd-gfx] [PATCH] drm/amdgpu: fix num_rbs exposed to userspace

[Alex Deucher]

On Fri, Jun 17, 2016 at 1:36 PM, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
> On 17.06.2016 17:37, Alex Deucher wrote:
>>
>> On Fri, Jun 17, 2016 at 11:31 AM, Nicolai Hähnle <nhaehnle at gmail.com>
>> wrote:
>>>
>>> On 17.06.2016 16:20, Alex Deucher wrote:
>>>>
>>>>
>>>> This was accidently broken for harvest cards when the
>>>> code was refactored for Polaris support.
>>>>
>>>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>>>> Cc: stable at vger.kernel.org
>>>> ---
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>>> index 9ab28ca..e5c22cd 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>>> @@ -459,7 +459,7 @@ static int amdgpu_info_ioctl(struct drm_device *dev,
>>>> void *data, struct drm_file
>>>>                          dev_info.max_memory_clock =
>>>> adev->pm.default_mclk
>>>> * 10;
>>>>                  }
>>>>                  dev_info.enabled_rb_pipes_mask =
>>>> adev->gfx.config.backend_enable_mask;
>>>> -               dev_info.num_rb_pipes = adev->gfx.config.num_rbs;
>>>> +               dev_info.num_rb_pipes =
>>>> adev->gfx.config.max_backends_per_se;
>>>
>>>
>>>
>>> At a glance, that looks suspicious to me. num_rb_pipes becomes rb_pipes
>>> in
>>> libdrmm and then num_render_backends. We divide num_render_backends by
>>> the
>>> number of SEs * SHs in radeonsi.
>>>
>>> In a nutshell, radeonsi expects this to be the total number of RBs
>>> (including disabled/harvested ones).
>>
>>
>> Right.  that's what this patch does.
>> adev->gfx.config.max_backends_per_se is the total number of RBs per SE
>> available on the asic. adev->gfx.config.num_rbs is the total number of
>> enabled RBs (max - disabled).  For non-harvest cards, they are the
>> same.
>
>
> But the total number of RBs is different from the total number of RBs per
> SE...
>

Whoops yes.  New patch sent.

Alex

> Nicolai
>
>
>>
>> Alex
>>
>>>
>>> Nicolai
>>>
>>>
>>>>                  dev_info.num_hw_gfx_contexts =
>>>> adev->gfx.config.max_hw_contexts;
>>>>                  dev_info._pad = 0;
>>>>                  dev_info.ids_flags = 0;
>>>>
>>>
>