[RFC v2 04/15] drm/amdgpu: introduce a flag to track refcount held for features

[Lazar, Lijo]

On 1/13/2025 7:12 AM, Jiang Liu wrote:
> Currently we track the refcount on ras block object for features by
> checking `if (obj && amdgpu_ras_is_feature_enabled(adev, head))`,
> which is a little unreliable. So introduce a dedicated flag to track
> the reference count.
> 

Please clarify more on this. I see  con->features available to track the
status.

Thanks,
Lijo

> Signed-off-by: Jiang Liu <gerry at linux.alibaba.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu.h     | 1 +
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 9 +++++++--
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 09b63a622728..24ef39b706e3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -380,6 +380,7 @@ int amdgpu_ip_block_resume(struct amdgpu_ip_block *ip_block);
>  enum amdgpu_marker {
>  	// Markers for ras blocks.
>  	AMDGPU_MARKER_RAS_DEBUGFS,
> +	AMDGPU_MARKER_RAS_FEATURE,
>  	// Markers for IRQs, used for both ip blocks and ras blocks.
>  	AMDGPU_MARKER_IRQ0 = 32,
>  	AMDGPU_MARKER_IRQ1,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> index 6b508a9b1abe..f0cd14ff78a7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> @@ -775,15 +775,20 @@ static int __amdgpu_ras_feature_enable(struct amdgpu_device *adev,
>  			obj = amdgpu_ras_create_obj(adev, head);
>  			if (!obj)
>  				return -EINVAL;
> -		} else {
> +			amdgpu_ras_set_marker(adev, head, AMDGPU_MARKER_RAS_FEATURE);
> +		} else if (!amdgpu_ras_test_marker(adev, head,
> +						   AMDGPU_MARKER_RAS_FEATURE)) {
>  			/* In case we create obj somewhere else */
>  			get_obj(obj);
> +			amdgpu_ras_set_marker(adev, head, AMDGPU_MARKER_RAS_FEATURE);
>  		}
>  		con->features |= BIT(head->block);
>  	} else {
>  		if (obj && amdgpu_ras_is_feature_enabled(adev, head)) {
>  			con->features &= ~BIT(head->block);
> -			put_obj(obj);
> +			if (amdgpu_ras_test_and_clear_marker(adev, head,
> +							     AMDGPU_MARKER_RAS_FEATURE))
> +				put_obj(obj);
>  		}
>  	}
>