Re: [PATCH] drm/amdgpu: Make amdgpu_dma_buf_attach() return paths consistent

["Christian König" <christian.koenig@amd.com>]

On 3/12/26 14:44, Srinivasan Shanmugam wrote:
> amdgpu_dma_buf_attach() locks bo->tbo.base.resv before updating the BO
> sharing state and unlocks it before returning.
> 
> Return the local status variable after the unlock so the function has a
> single consistent success return path, which avoids the Smatch warning
> about inconsistent reservation lock handling.

Mhm, that doesn't looks correct to me.

> 
> Fixes the below:
> drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c:111 amdgpu_dma_buf_attach() warn: inconsistent returns 'bo->tbo.base.resv'.

As far as I can see neither that warning nor the fact that returning the error (which is always 0 at that point) would fix it makes sense to me.

What exactly is going on here?

Regards,
Christian.

> 
> Fixes: 6e6db2722c28 ("drm/amdgpu: add independent DMA-buf export v8")
> Cc: Dan Carpenter <dan.carpenter@linaro.org>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> index 656c267dbe58..9cf240ad5471 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> @@ -108,7 +108,7 @@ static int amdgpu_dma_buf_attach(struct dma_buf *dmabuf,
>  
>  	dma_resv_unlock(bo->tbo.base.resv);
>  
> -	return 0;
> +	return r;
>  }
>  
>  /**