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

["Nicolai Hähnle" <nhaehnle@gmail.com>]

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@amd.com>
> Cc: stable@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).

Nicolai

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