Re: [PATCH v4 12/23] ASoC: simple-card: Support DPCM DAI link with multiple Codecs

From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
To: Sameer Pujar <spujar@nvidia.com>
Cc: <broonie@kernel.org>, <perex@perex.cz>, <tiwai@suse.com>,
	<robh+dt@kernel.org>, <lgirdwood@gmail.com>,
	<thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
	<digetx@gmail.com>, <alsa-devel@alsa-project.org>,
	<linux-tegra@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<sharadg@nvidia.com>, <mkumard@nvidia.com>,
	<viswanathl@nvidia.com>, <rlokhande@nvidia.com>,
	<dramesh@nvidia.com>, <atalambedu@nvidia.com>,
	<nwartikar@nvidia.com>, <swarren@nvidia.com>,
	<nicoleotsuka@gmail.com>
Subject: Re: [PATCH v4 12/23] ASoC: simple-card: Support DPCM DAI link with multiple Codecs
Date: 29 Jun 2020 10:24:37 +0900	[thread overview]
Message-ID: <874kqu1x70.wl-kuninori.morimoto.gx@renesas.com> (raw)
In-Reply-To: <1593233625-14961-13-git-send-email-spujar@nvidia.com>

Hi Sameer

> The simple-card driver supports multiple CPU and single Codec entries
> for DPCM DAI links. In some cases it is required to have multiple
> CPU/Codecs. Currently parsing logic for DPCM link loops over all
> children of DAI link but assumes that there is a single Codec entry.
> When DAI link has multiple Codecs it considers only the first Codec
> entry and remaining Codecs are wrongly treated as CPU. This happens
> because first Codec is used as reference for parsing all other child
> nodes.
(snip)
> @@ -137,8 +136,13 @@ static int simple_dai_link_of_dpcm(struct asoc_simple_priv *priv,
>  	 * Codec |return|Pass
>  	 * np
>  	 */
> -	if (li->cpu == (np == codec))
> -		return 0;
> +	if (li->cpu) {
> +		if (!strcmp(np->name, "codec"))
> +			return 0;
> +	} else {
> +		if (!strcmp(np->name, "cpu"))
> +			return 0;
> +	}

Checking node name is maybe nice idea,
but please consider "prefix" here.

Maybe base issue for multiple codec support
is that simple_for_each_link() is caring first codec only ?

	simple_for_each_link(...)
	{
		...
		do {
=>			/* get codec */
=>			codec = of_get_child_by_name(...);
			...
		}
	}

Remove above and having simple_node_is_codec(np, xxx) function
or something can help it ?

Thank you for your help !!

Best regards
---
Kuninori Morimoto