Re: [PATCH v4 03/14] dma-buf/fence-chain: Add fence deadline support

[Tvrtko Ursulin]

On 18/02/2023 21:15, Rob Clark wrote:
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
>
> Propagate the deadline to all the fences in the chain.
>
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> Reviewed-by: Christian König <christian.koenig@xxxxxxx> for this one.
> ---
>   drivers/dma-buf/dma-fence-chain.c | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
> index a0d920576ba6..4684874af612 100644
> --- a/drivers/dma-buf/dma-fence-chain.c
> +++ b/drivers/dma-buf/dma-fence-chain.c
> @@ -206,6 +206,18 @@ static void dma_fence_chain_release(struct dma_fence *fence)
>   	dma_fence_free(fence);
>   }
>   
> +
> +static void dma_fence_chain_set_deadline(struct dma_fence *fence,
> +					 ktime_t deadline)
> +{
> +	dma_fence_chain_for_each(fence, fence) {
> +		struct dma_fence_chain *chain = to_dma_fence_chain(fence);
> +		struct dma_fence *f = chain ? chain->fence : fence;

Low level comment - above two lines could be replaced with:

	struct dma_fence *f = dma_fence_chain_contained(fence);

Although to be fair I am not sure that wouldn't be making it less 
readable. From the point of view that fence might not be a chain, so 
dma_fence_chain_contained() reads a bit dodgy as an API.

Regards,

Tvrtko

> +
> +		dma_fence_set_deadline(f, deadline);
> +	}
> +}
> +
>   const struct dma_fence_ops dma_fence_chain_ops = {
>   	.use_64bit_seqno = true,
>   	.get_driver_name = dma_fence_chain_get_driver_name,
> @@ -213,6 +225,7 @@ const struct dma_fence_ops dma_fence_chain_ops = {
>   	.enable_signaling = dma_fence_chain_enable_signaling,
>   	.signaled = dma_fence_chain_signaled,
>   	.release = dma_fence_chain_release,
> +	.set_deadline = dma_fence_chain_set_deadline,
>   };
>   EXPORT_SYMBOL(dma_fence_chain_ops);
>