Re: [PATCH 3/5] dma-buf: return only unsignaled fences in dma_fence_unwrap_for_each v3

[Daniel Vetter <daniel@ffwll.ch>]

On Fri, May 06, 2022 at 04:10:07PM +0200, Christian König wrote:
> dma_fence_chain containers cleanup signaled fences automatically, so
> filter those out from arrays as well.
> 
> v2: fix missing walk over the array
> v3: massively simplify the patch and actually update the description.
> 
> Signed-off-by: Christian König <christian.koenig@amd.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
>  include/linux/dma-fence-unwrap.h | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/dma-fence-unwrap.h b/include/linux/dma-fence-unwrap.h
> index e7c219da4ed7..a4d342fef8e0 100644
> --- a/include/linux/dma-fence-unwrap.h
> +++ b/include/linux/dma-fence-unwrap.h
> @@ -43,9 +43,13 @@ struct dma_fence *dma_fence_unwrap_next(struct dma_fence_unwrap *cursor);
>   * Unwrap dma_fence_chain and dma_fence_array containers and deep dive into all
>   * potential fences in them. If @head is just a normal fence only that one is
>   * returned.
> + *
> + * Note that signalled fences are opportunistically filtered out, which
> + * means the iteration is potentially over no fence at all.
>   */
>  #define dma_fence_unwrap_for_each(fence, cursor, head)			\
>  	for (fence = dma_fence_unwrap_first(head, cursor); fence;	\
> -	     fence = dma_fence_unwrap_next(cursor))
> +	     fence = dma_fence_unwrap_next(cursor))			\
> +		if (!dma_fence_is_signaled(fence))
>  
>  #endif
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch