Re: [PATCH 4/6] drm/amdgpu: Remove redundant state change after validation.

["Christian König" <christian.koenig@amd.com>]

Am 31.10.23 um 14:40 schrieb Tatsuyuki Ishi:
> All the state changes are handled in the TTM move callback; doing it again
> here just leads to more confusion.

The state move here is because we need to track which PDs/PTs are 
already validated and which have new locations reflected in the PDEs.

With this change here you will sooner or later run into PDE corruption.

>
> The table update remains here because it needs to be done exactly once,
> while doing it in the move callback will result it getting triggered twice,
> once by the actual BO and once by the shadow BO.

The table update isn't done in the move callback because you can't take 
the appropriate locks there.

Regards,
Christian.


>
> Signed-off-by: Tatsuyuki Ishi <ishitatsuyuki@gmail.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 7 ++-----
>   1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 01d31891cd05..50f7cee639ac 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -495,12 +495,9 @@ int amdgpu_vm_validate_pt_bos(struct amdgpu_device *adev, struct amdgpu_vm *vm,
>   				return r;
>   		}
>   
> -		if (bo->tbo.type != ttm_bo_type_kernel) {
> -			amdgpu_vm_bo_moved(bo_base);
> -		} else {
> +		if (bo->tbo.type == ttm_bo_type_kernel)
>   			vm->update_funcs->map_table(to_amdgpu_bo_vm(bo));
> -			amdgpu_vm_bo_relocated(bo_base);
> -		}
> +
>   		spin_lock(&vm->status_lock);
>   	}
>   	spin_unlock(&vm->status_lock);