[PATCH] drm/amdgpu: take runtime pm reference when we attach a buffer

[Alex Deucher]

On Fri, Dec 4, 2020 at 3:41 PM Alex Deucher <alexdeucher at gmail.com> wrote:
>
> And drop it when we detach.  If the shared buffer is in vram,
> we need to make sure we don't put the device into runtime
> suspend.
>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>


Ping?  Any thoughts on this?  We really only need this for p2p since
device memory in involved, but I'm not sure of the best way to handle
that.

Alex


> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> index 5b465ab774d1..f63f182f37f9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> @@ -40,6 +40,7 @@
>  #include <linux/dma-buf.h>
>  #include <linux/dma-fence-array.h>
>  #include <linux/pci-p2pdma.h>
> +#include <linux/pm_runtime.h>
>
>  /**
>   * amdgpu_gem_prime_vmap - &dma_buf_ops.vmap implementation
> @@ -187,9 +188,13 @@ static int amdgpu_dma_buf_attach(struct dma_buf *dmabuf,
>         if (attach->dev->driver == adev->dev->driver)
>                 return 0;
>
> +       r = pm_runtime_get_sync(adev_to_drm(adev)->dev);
> +       if (r < 0)
> +               goto out;
> +
>         r = amdgpu_bo_reserve(bo, false);
>         if (unlikely(r != 0))
> -               return r;
> +               goto out;
>
>         /*
>          * We only create shared fences for internal use, but importers
> @@ -201,11 +206,15 @@ static int amdgpu_dma_buf_attach(struct dma_buf *dmabuf,
>          */
>         r = __dma_resv_make_exclusive(bo->tbo.base.resv);
>         if (r)
> -               return r;
> +               goto out;
>
>         bo->prime_shared_count++;
>         amdgpu_bo_unreserve(bo);
>         return 0;
> +
> +out:
> +       pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
> +       return r;
>  }
>
>  /**
> @@ -225,6 +234,9 @@ static void amdgpu_dma_buf_detach(struct dma_buf *dmabuf,
>
>         if (attach->dev->driver != adev->dev->driver && bo->prime_shared_count)
>                 bo->prime_shared_count--;
> +
> +       pm_runtime_mark_last_busy(adev_to_drm(adev)->dev);
> +       pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
>  }
>
>  /**
> --
> 2.25.4
>