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Date:   Mon, 8 Aug 2022 21:44:11 +0200
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Subject: Re: [PATCH RFC] dma-buf: To check DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT
 status on debug
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To:     Arvind Yadav <Arvind.Yadav@amd.com>, andrey.grodzovsky@amd.com,
        shashank.sharma@amd.com, amaranath.somalapuram@amd.com,
        Luben.Tuikov@amd.com, Alexander.Deucher@amd.com,
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References: <20220804121938.622630-1-Arvind.Yadav@amd.com>
From:   =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
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Am 04.08.22 um 14:19 schrieb Arvind Yadav:
> If core DMA-buf framework forgets to call dma_fence_enable_signaling()
> before calling the dma_fence_is_signaled(). To handle this scenario on
> debug kernel the DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT needs to be checked
> before checking the actual signaling status.
>
> Signed-off-by: Arvind Yadav <Arvind.Yadav@amd.com>
> ---
>   include/linux/dma-fence.h | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
> index 775cdc0b4f24..7c95c8d5e5f5 100644
> --- a/include/linux/dma-fence.h
> +++ b/include/linux/dma-fence.h
> @@ -428,6 +428,10 @@ dma_fence_is_signaled_locked(struct dma_fence *fence)
>   static inline bool
>   dma_fence_is_signaled(struct dma_fence *fence)
>   {
> +#ifdef CONFIG_DEBUG_FS
> +	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags))
> +		return true;

The logic is just inverted. The test should be !test_bit(...) return false;

And please give that some testing as well.

Regards,
Christian.

> +#endif
>   	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
>   		return true;
>