Re: [PATCH 11/11] drm/amdgpu: WIP sync amdgpu_ttm_fill_mem only to kernel fences

["Khatri, Sunil" <sukhatri@amd.com>]

[-- Attachment #1: Type: text/plain, Size: 3067 bytes --]

It would be good if we add some explanation of why we used 
DMA_RESV_USAGE_BOOKKEEP for buffer copy and for fill we use 
DMA_RESV_USAGE_KERNEL.
Either as a comment or in commit message would help new folks to get a 
hold on it. Other than that its a good catch.

Acked-by: Sunil Khatri <sunil.khatri@amd.com>


For my understanding:
A copy buffer could involve buffer move to different domains too and 
might need to depend on all fences including read/write and internal 
kernel fences. At the same time buffer fill only
writes to the memory and only depend on kernel implicit sync fences ?

Regards
Sunil Khatri

On 11-03-2026 12:43 am, Christian König wrote:
> That's not even remotely correct, but should unblock testing for now.
>
> Signed-off-by: Christian König<christian.koenig@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 12 +++++++-----
>   1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 714fd8d12ca5..69f52a078022 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -2428,12 +2428,14 @@ static int amdgpu_ttm_prepare_job(struct amdgpu_device *adev,
>   				  struct amdgpu_ttm_buffer_entity *entity,
>   				  unsigned int num_dw,
>   				  struct dma_resv *resv,
> +				  enum dma_resv_usage usage,
>   				  bool vm_needs_flush,
>   				  struct amdgpu_job **job,
>   				  u64 k_job_id)
>   {
>   	enum amdgpu_ib_pool_type pool = AMDGPU_IB_POOL_DELAYED;
>   	int r;
> +
>   	r = amdgpu_job_alloc_with_ib(adev, &entity->base,
>   				     AMDGPU_FENCE_OWNER_UNDEFINED,
>   				     num_dw * 4, pool, job, k_job_id);
> @@ -2449,8 +2451,7 @@ static int amdgpu_ttm_prepare_job(struct amdgpu_device *adev,
>   	if (!resv)
>   		return 0;
>   
> -	return drm_sched_job_add_resv_dependencies(&(*job)->base, resv,
> -						   DMA_RESV_USAGE_BOOKKEEP);
> +	return drm_sched_job_add_resv_dependencies(&(*job)->base, resv, usage);
>   }
>   
>   int amdgpu_copy_buffer(struct amdgpu_device *adev,
> @@ -2479,9 +2480,9 @@ int amdgpu_copy_buffer(struct amdgpu_device *adev,
>   	max_bytes = adev->mman.buffer_funcs->copy_max_bytes;
>   	num_loops = DIV_ROUND_UP(byte_count, max_bytes);
>   	num_dw = ALIGN(num_loops * adev->mman.buffer_funcs->copy_num_dw, 8);
> -	r = amdgpu_ttm_prepare_job(adev, entity, num_dw,
> -				   resv, vm_needs_flush, &job,
> -				   AMDGPU_KERNEL_JOB_ID_TTM_COPY_BUFFER);
> +	r = amdgpu_ttm_prepare_job(adev, entity, num_dw, resv,
> +				   DMA_RESV_USAGE_BOOKKEEP, vm_needs_flush,
> +				   &job, AMDGPU_KERNEL_JOB_ID_TTM_COPY_BUFFER);
>   	if (r)
>   		goto error_free;
>   
> @@ -2524,6 +2525,7 @@ static int amdgpu_ttm_fill_mem(struct amdgpu_device *adev,
>   	num_loops = DIV_ROUND_UP_ULL(byte_count, max_bytes);
>   	num_dw = ALIGN(num_loops * adev->mman.buffer_funcs->fill_num_dw, 8);
>   	r = amdgpu_ttm_prepare_job(adev, entity, num_dw, resv,
> +				   DMA_RESV_USAGE_KERNEL,
>   				   vm_needs_flush, &job, k_job_id);
>   	if (r)
>   		return r;

[-- Attachment #2: Type: text/html, Size: 3692 bytes --]