[PATCH] drm/amdkfd: fix partition query when setting up recommended sdma engines

[Lazar, Lijo]

On 8/8/2024 2:04 AM, Jonathan Kim wrote:
> When users dynamically set the partition mode through sysfs writes,
> this can lead to a double lock situation where the KFD is trying to take
> the partition lock when updating the recommended SDMA engines.
> Have the KFD do a lockless query instead to avoid this.
> This should work since the KFD always initializes synchronously after
> the KGD partition mode is set regardless of user or system setup.
> 
> Fixes: a0f548d7871e ("drm/amdkfd: allow users to target recommended SDMA engines")
> Signed-off-by: Jonathan Kim <jonathan.kim at amd.com>
> ---
>  drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> index 40771f8752cb..8fee89b8dd67 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> @@ -1287,7 +1287,7 @@ static void kfd_set_recommended_sdma_engines(struct kfd_topology_device *to_dev,
>  	int num_xgmi_nodes = adev->gmc.xgmi.num_physical_nodes;
>  	bool support_rec_eng = !amdgpu_sriov_vf(adev) && to_dev->gpu &&
>  		adev->aid_mask && num_xgmi_nodes &&
> -		(amdgpu_xcp_query_partition_mode(adev->xcp_mgr, AMDGPU_XCP_FL_NONE) ==
> +		(amdgpu_xcp_query_partition_mode(adev->xcp_mgr, AMDGPU_XCP_FL_LOCKED) ==
>  		      AMDGPU_SPX_PARTITION_MODE) &&

Replacing with (gpu->kfd->num_nodes == 1) may be better.

Thanks,
Lijo

>  		(!(adev->flags & AMD_IS_APU) && num_xgmi_nodes == 8);
>