Re: [PATCH v1 2/2] drm/amdgpu: delay ttm buffer func enablement on xgmi

[Alex Deucher]

On Tue, Jun 16, 2026 at 8:51 AM Pierre-Eric Pelloux-Prayer
<pierre-eric.pelloux-prayer@xxxxxxx> wrote:
>
> When amdgpu_init_minimal_xgmi is used, SDMA engines init
> is delayed so amdgpu_ttm_enable_buffer_funcs must be
> called later.
>
> Without this, the check for num_buffer_funcs_scheds will
> fail and using ttm buffer funcs later will fail.
>
> Fixes: 3a5da695c8d1 ("drm/amdgpu: only use working sdma schedulers for ttm")
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@xxxxxxx>

Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 3 ++-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c   | 2 ++
>  2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 57e10afb4714..2e8954fa5c40 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -2479,7 +2479,8 @@ static int amdgpu_device_ip_init(struct amdgpu_device *adev)
>         if (r)
>                 goto init_failed;
>
> -       amdgpu_ttm_enable_buffer_funcs(adev);
> +       if (amdgpu_ip_member_of_hwini(adev, AMD_IP_BLOCK_TYPE_SDMA))
> +               amdgpu_ttm_enable_buffer_funcs(adev);
>
>         /* Don't init kfd if whole hive need to be reset during init */
>         if (adev->init_lvl->level != AMDGPU_INIT_LEVEL_MINIMAL_XGMI) {
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
> index faac80a8a6eb..c0dca209335e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
> @@ -1663,6 +1663,8 @@ static void amdgpu_xgmi_reset_on_init_work(struct work_struct *work)
>                 if (r && r != -EHWPOISON)
>                         dev_err(tmp_adev->dev,
>                                 "error during bad page data initialization");
> +
> +               amdgpu_ttm_enable_buffer_funcs(tmp_adev);
>         }
>  }
>
> --
> 2.43.0
>