Re: [PATCH] dma-buf: Fix missing excl fence waiting

[Pan, Xinhui]

sorry, paste a wrong patch. will send out v2.


> 2020å2æ23æ 19:56ïPan, Xinhui <Xinhui.Pan@xxxxxxx> åéï
> 
> If shared fence list is not empty, even we want to test all fences, excl fence is ignored.
> That is abviously wrong, so fix it.
> 
> Signed-off-by: xinhui pan <xinhui.pan@xxxxxxx>
> ---
> drivers/dma-buf/dma-resv.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
> index 4264e64788c4..44dc64c547c6 100644
> --- a/drivers/dma-buf/dma-resv.c
> +++ b/drivers/dma-buf/dma-resv.c
> @@ -632,14 +632,14 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
>  */
> bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
> {
> -	unsigned seq, shared_count;
> +	unsigned int seq, shared_count, left;
> 	int ret;
> 
> 	rcu_read_lock();
> retry:
> 	ret = true;
> 	shared_count = 0;
> -	seq = read_seqcount_begin(&obj->seq);
> +	left = seq = read_seqcount_begin(&obj->seq);
> 
> 	if (test_all) {
> 		unsigned i;
> @@ -647,7 +647,7 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
> 		struct dma_resv_list *fobj = rcu_dereference(obj->fence);
> 
> 		if (fobj)
> -			shared_count = fobj->shared_count;
> +			left = shared_count = fobj->shared_count;
> 
> 		for (i = 0; i < shared_count; ++i) {
> 			struct dma_fence *fence = rcu_dereference(fobj->shared[i]);
> @@ -657,13 +657,14 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
> 				goto retry;
> 			else if (!ret)
> 				break;
> +			left--;
> 		}
> 
> 		if (read_seqcount_retry(&obj->seq, seq))
> 			goto retry;
> 	}
> 
> -	if (!shared_count) {
> +	if (!left) {
> 		struct dma_fence *fence_excl = rcu_dereference(obj->fence_excl);
> 
> 		if (fence_excl) {
> -- 
> 2.21.0 (Apple Git-122)
> 
>