[PATCH] drm/amd/amdgpu: Remove double lock from gfx v6

[Christian König]

Am 07.09.2016 um 14:07 schrieb Tom St Denis:
> The function gfx_v6_0_get_cu_info() was taking the
> grbm_idx_mutex which was then taken by a dependent
> function gfx_v6_0_get_cu_active_bitmap().
>
> This patch removes the select from the parent function
> to avoid the double lock.
>
> Signed-off-by: Tom St Denis <tom.stdenis at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c | 4 ----
>   1 file changed, 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
> index a6b76170b9c5..a1484b8f7eb2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
> @@ -3193,13 +3193,11 @@ static void gfx_v6_0_get_cu_info(struct amdgpu_device *adev)
>   
>   	memset(cu_info, 0, sizeof(*cu_info));
>   
> -	mutex_lock(&adev->grbm_idx_mutex);
>   	for (i = 0; i < adev->gfx.config.max_shader_engines; i++) {
>   		for (j = 0; j < adev->gfx.config.max_sh_per_se; j++) {
>   			mask = 1;
>   			ao_bitmap = 0;
>   			counter = 0;
> -			gfx_v6_0_select_se_sh(adev, i, j, 0xffffffff);
>   			bitmap = gfx_v6_0_get_cu_active_bitmap(adev, i, j);
>   			cu_info->bitmap[i][j] = bitmap;
>   
> @@ -3215,8 +3213,6 @@ static void gfx_v6_0_get_cu_info(struct amdgpu_device *adev)
>   			ao_cu_mask |= (ao_bitmap << (i * 16 + j * 8));
>   		}
>   	}
> -	gfx_v6_0_select_se_sh(adev, 0xffffffff, 0xffffffff, 0xffffffff);
> -	mutex_unlock(&adev->grbm_idx_mutex);
>   
>   	cu_info->number = active_cu_number;
>   	cu_info->ao_cu_mask = ao_cu_mask;