[PATCH v2 3/9] ASoC: audio-graph: Identify 'no_pcm' DAI links for DPCM

Kuninori Morimoto kuninori.morimoto.gx at renesas.com
Tue Aug 18 04:41:57 CEST 2020


Hi Sameer

> PCM devices are created for FE dai links with 'no-pcm' flag as '0'.
> Such DAI links have CPU component which implement either pcm_construct()
> or pcm_new() at component or dai level respectively. Based on this,
> current patch exposes a helper function to identify such components
> and populate 'no_pcm' flag for DPCM DAI link.
> 
> This helps to have BE<->BE component links where PCM devices need
> not be created for CPU component involved in such links.
> 
> Signed-off-by: Sameer Pujar <spujar at nvidia.com>
> ---
(snip)
> @@ -259,6 +270,16 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv *priv,
>  		if (ret < 0)
>  			goto out_put_node;
>  
> +		/*
> +		 * In BE<->BE connections it is not required to create
> +		 * PCM devices at CPU end of the dai link and thus 'no_pcm'
> +		 * flag needs to be set. It is useful when there are many
> +		 * BE components and some of these have to be connected to
> +		 * form a valid audio path.
> +		 */
> +		if (!soc_component_is_pcm(cpus))
> +			dai_link->no_pcm = 1;
> +

For safety, I want to judge with data->component_chaining.

	if (data->component_chaining &&
	    !soc_component_is_pcm(cpus))
			dai_link->no_pcm = 1;

Thank you for your help !!

Best regards
---
Kuninori Morimoto


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