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Date:   Mon, 5 Sep 2022 13:21:07 +0200
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Subject: Re: [PATCH 1/4] dma-buf: Check status of enable-signaling bit 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,
        Arunpravin.PaneerSelvam@amd.com, sumit.semwal@linaro.org,
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        linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
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References: <20220905105653.13670-1-Arvind.Yadav@amd.com>
 <20220905105653.13670-2-Arvind.Yadav@amd.com>
From:   =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
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Am 05.09.22 um 12:56 schrieb Arvind Yadav:
> The core DMA-buf framework needs to enable signaling
> before the fence is signaled. The core DMA-buf framework
> can forget to enable signaling before the fence is signaled.
> To avoid this scenario on the debug kernel, check the
> DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT status bit before checking
> the signaling bit status to confirm that enable_signaling
> is enabled.

You might want to put this patch at the end of the series to avoid 
breaking the kernel in between.

>
> Signed-off-by: Arvind Yadav <Arvind.Yadav@amd.com>
> ---
>   include/linux/dma-fence.h | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
> index 775cdc0b4f24..60c0e935c0b5 100644
> --- a/include/linux/dma-fence.h
> +++ b/include/linux/dma-fence.h
> @@ -428,6 +428,11 @@ dma_fence_is_signaled_locked(struct dma_fence *fence)
>   static inline bool
>   dma_fence_is_signaled(struct dma_fence *fence)
>   {
> +#ifdef CONFIG_DEBUG_FS

CONFIG_DEBUG_FS is certainly wrong, probably better to check for 
CONFIG_DEBUG_WW_MUTEX_SLOWPATH here.

Apart from that looks good to me,
Christian.

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