[PATCH 2/4] dma-buf: fix dma_resv_test_signaled test_all handling v2

[Daniel Vetter]

On Fri, Jul 02, 2021 at 01:16:40PM +0200, Christian König wrote:
> As the name implies if testing all fences is requested we
> should indeed test all fences and not skip the exclusive
> one because we see shared ones.
> 
> v2: fix logic once more
> 
> Signed-off-by: Christian König <christian.koenig at amd.com>

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

> ---
>  drivers/dma-buf/dma-resv.c | 33 ++++++++++++---------------------
>  1 file changed, 12 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
> index 4ab02b6c387a..18dd5a6ca06c 100644
> --- a/drivers/dma-buf/dma-resv.c
> +++ b/drivers/dma-buf/dma-resv.c
> @@ -618,25 +618,21 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
>   */
>  bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all)
>  {
> -	unsigned int seq, shared_count;
> +	struct dma_fence *fence;
> +	unsigned int seq;
>  	int ret;
>  
>  	rcu_read_lock();
>  retry:
>  	ret = true;
> -	shared_count = 0;
>  	seq = read_seqcount_begin(&obj->seq);
>  
>  	if (test_all) {
>  		struct dma_resv_list *fobj = dma_resv_shared_list(obj);
> -		unsigned int i;
> -
> -		if (fobj)
> -			shared_count = fobj->shared_count;
> +		unsigned int i, shared_count;
>  
> +		shared_count = fobj ? fobj->shared_count : 0;
>  		for (i = 0; i < shared_count; ++i) {
> -			struct dma_fence *fence;
> -
>  			fence = rcu_dereference(fobj->shared[i]);
>  			ret = dma_resv_test_signaled_single(fence);
>  			if (ret < 0)
> @@ -644,24 +640,19 @@ bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all)
>  			else if (!ret)
>  				break;
>  		}
> -
> -		if (read_seqcount_retry(&obj->seq, seq))
> -			goto retry;
>  	}
>  
> -	if (!shared_count) {
> -		struct dma_fence *fence_excl = dma_resv_excl_fence(obj);
> -
> -		if (fence_excl) {
> -			ret = dma_resv_test_signaled_single(fence_excl);
> -			if (ret < 0)
> -				goto retry;
> +	fence = dma_resv_excl_fence(obj);
> +	if (ret && fence) {
> +		ret = dma_resv_test_signaled_single(fence);
> +		if (ret < 0)
> +			goto retry;
>  
> -			if (read_seqcount_retry(&obj->seq, seq))
> -				goto retry;
> -		}
>  	}
>  
> +	if (read_seqcount_retry(&obj->seq, seq))
> +		goto retry;
> +
>  	rcu_read_unlock();
>  	return ret;
>  }
> -- 
> 2.25.1
> 

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