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Date:   30 Jun 2020 15:07:55 +0900
Message-ID: <87h7utytlx.wl-kuninori.morimoto.gx@renesas.com>
From:   Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
To:     Sameer Pujar <spujar@nvidia.com>
Cc:     <broonie@kernel.org>, <perex@perex.cz>, <tiwai@suse.com>,
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        <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 15/23] ASoC: soc-core: Identify 'no_pcm' DAI links for DPCM
In-Reply-To: <1593233625-14961-16-git-send-email-spujar@nvidia.com>
References: <1593233625-14961-1-git-send-email-spujar@nvidia.com>
        <1593233625-14961-16-git-send-email-spujar@nvidia.com>
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Hi Sameer

> PCM devices are created for dai links with 'no-pcm' flag as '0'.
> Such DAI links have CPU component which implement pcm_construct()
> and pcm_destruct() callbacks. 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 components involved in the links.
> 
> Signed-off-by: Sameer Pujar <spujar@nvidia.com>
> ---
(snip)
> +bool soc_component_is_pcm(struct snd_soc_dai_link_component *dlc)
> +{
> +	struct snd_soc_component *component;
> +	struct snd_soc_dai *dai;
> +
> +	for_each_component(component) {
> +		if (!component->driver)
> +			continue;
> +
> +		for_each_component_dais(component, dai) {
> +			if (!dai->name || !dlc->dai_name)
> +				continue;
> +
> +			if (strcmp(dai->name, dlc->dai_name))
> +				continue;
> +
> +			if (component->driver->pcm_construct)
> +				return true;
> +		}
> +	}
> +
> +	return false;
> +}

At least my CPU driver doesn't use component:pcm_construct
but is using DAI:pcm_new for some reasons.
I'm not sure checking DAI:pcm here is enough, or not...

Thank you for your help !!

Best regards
---
Kuninori Morimoto