[PATCH 1/3] drm/amdgpu/sdma: add begin_use/end_use helpers

[Alex Deucher]

On Fri, Dec 8, 2023 at 5:19 PM Alex Deucher <alexander.deucher at amd.com> wrote:
>
> Add helper functions to disallow GFXOFF while SDMA has work.
> This should avoid corner cases where GFXOFF is erroneously
> entered when SDMA is still active.  For now just allow/disallow
> GFXOFF in the begin and end helpers until we root cause the
> issue.  This should not impact power as SDMA usage is pretty
> minimal and GFXOSS should not be active when SDMA is active
> anyway, this just makes it explicit.
>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>

Since sdma5.2 is the only version that currently needs this I think we
can just squash this all into sdma5.2.  There may even be 5.2.x
variants that don't need this.  Better to keep it all in that code.
Will send out a v2.

Alex

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c | 14 ++++++++++++++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h |  3 +++
>  2 files changed, 17 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> index 1d9d187de6ee..d4b08d03970c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> @@ -326,3 +326,17 @@ int amdgpu_sdma_ras_sw_init(struct amdgpu_device *adev)
>
>         return 0;
>  }
> +
> +void amdgpu_sdma_ring_begin_use(struct amdgpu_ring *ring)
> +{
> +       struct amdgpu_device *adev = ring->adev;
> +
> +       amdgpu_gfx_off_ctrl(adev, false);
> +}
> +
> +void amdgpu_sdma_ring_end_use(struct amdgpu_ring *ring)
> +{
> +       struct amdgpu_device *adev = ring->adev;
> +
> +       amdgpu_gfx_off_ctrl(adev, true);
> +}
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
> index 173a2a308078..b52d16829204 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
> @@ -171,4 +171,7 @@ void amdgpu_sdma_destroy_inst_ctx(struct amdgpu_device *adev,
>          bool duplicate);
>  int amdgpu_sdma_ras_sw_init(struct amdgpu_device *adev);
>
> +void amdgpu_sdma_ring_begin_use(struct amdgpu_ring *ring);
> +void amdgpu_sdma_ring_end_use(struct amdgpu_ring *ring);
> +
>  #endif
> --
> 2.42.0
>