[PATCH] drm/amdgpu/mes: refine for maximum packet execution

[Christian König]

Am 23.07.24 um 10:27 schrieb Jack Xiao:
> Only allow API_NUMBER_OF_COMMAND_MAX packet in mes ring buffer,
> refine the code for maximum packet execution.
>
> Signed-off-by: Jack Xiao <Jack.Xiao at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 2 ++
>   drivers/gpu/drm/amd/amdgpu/mes_v11_0.c   | 2 +-
>   drivers/gpu/drm/amd/amdgpu/mes_v12_0.c   | 2 +-
>   3 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> index ad49cecb20b8..dfe487521a4a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> @@ -212,6 +212,8 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
>   	 */
>   	if (ring->funcs->type == AMDGPU_RING_TYPE_KIQ)
>   		sched_hw_submission = max(sched_hw_submission, 256);
> +	else if (ring->funcs->type == AMDGPU_RING_TYPE_MES)
> +		sched_hw_submission = 32;

Yeah that looks like it makes sense.

>   	else if (ring == &adev->sdma.instance[0].page)
>   		sched_hw_submission = 256;
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/mes_v11_0.c b/drivers/gpu/drm/amd/amdgpu/mes_v11_0.c
> index 68c74adf79f1..951f13e01ee9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/mes_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/mes_v11_0.c
> @@ -198,7 +198,7 @@ static int mes_v11_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
>   
>   	seq = ++ring->fence_drv.sync_seq;
>   	r = amdgpu_fence_wait_polling(ring,
> -				      seq - ring->fence_drv.num_fences_mask,
> +				      seq - (API_NUMBER_OF_COMMAND_MAX/2 - 1),

This looks a bit questionable. amdgpu_fence_wait_polling() doesn't apply 
the fence mask to the polled value.

So what happens if that overruns?

Additional to that we should really keep that logic in 
amdgpu_fence_emit_polling() and not each individual MES generation.

Regards,
Christian.

>   				      timeout);
>   	if (r < 1)
>   		goto error_undo;
> diff --git a/drivers/gpu/drm/amd/amdgpu/mes_v12_0.c b/drivers/gpu/drm/amd/amdgpu/mes_v12_0.c
> index 48e01206bcc4..dc65f28d1795 100644
> --- a/drivers/gpu/drm/amd/amdgpu/mes_v12_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/mes_v12_0.c
> @@ -184,7 +184,7 @@ static int mes_v12_0_submit_pkt_and_poll_completion(struct amdgpu_mes *mes,
>   
>   	seq = ++ring->fence_drv.sync_seq;
>   	r = amdgpu_fence_wait_polling(ring,
> -				      seq - ring->fence_drv.num_fences_mask,
> +				      seq - (API_NUMBER_OF_COMMAND_MAX/2 - 1),
>   				      timeout);
>   	if (r < 1)
>   		goto error_undo;