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Message-ID: <322002af-09e8-4d4c-bc85-81654c6b5f9d@linux.intel.com>
Date:   Wed, 25 Oct 2023 10:12:23 -0500
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Subject: Re: [PATCH 1/3] soundwire: qcom: drop unneeded DAI .set_stream
 callback
Content-Language: en-US
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Vinod Koul <vkoul@kernel.org>,
        Bard Liao <yung-chuan.liao@linux.intel.com>,
        Sanyog Kale <sanyog.r.kale@intel.com>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Banajit Goswami <bgoswami@quicinc.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>, linux-arm-msm@vger.kernel.org,
        alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
References: <20231025144601.268645-1-krzysztof.kozlowski@linaro.org>
From:   Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
In-Reply-To: <20231025144601.268645-1-krzysztof.kozlowski@linaro.org>
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On 10/25/23 09:45, Krzysztof Kozlowski wrote:
> Qualcomm Soundwire controller drivers do not support multi-link setups,
> so DAI .set_stream() callback will not be used.  What's more, if called
> it will overwrite the sdw_stream_runtime runtime set in DAI .startup
> (qcom_swrm_startup()) causing issues (unsupported multi-link error) when
> two Soundwire controllers are passed as codec DAIs.

This last sentence is confusing at best.

A controller can have one or more managers, each of whom can have one or
more peripherals.

only peripherals should expose codec DAIs, managers should expose CPU DAIs.

Put differently, the controller is the host part while the peripheral is
the codec part. "controllers passed as codec DAIs" is not really
possible, or this was a typo?

> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
>  drivers/soundwire/qcom.c | 11 -----------
>  1 file changed, 11 deletions(-)
> 
> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
> index f1b8d6ac5140..fe65c26c5281 100644
> --- a/drivers/soundwire/qcom.c
> +++ b/drivers/soundwire/qcom.c
> @@ -1267,16 +1267,6 @@ static int qcom_swrm_hw_free(struct snd_pcm_substream *substream,
>  	return 0;
>  }
>  
> -static int qcom_swrm_set_sdw_stream(struct snd_soc_dai *dai,
> -				    void *stream, int direction)
> -{
> -	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
> -
> -	ctrl->sruntime[dai->id] = stream;
> -
> -	return 0;
> -}
> -
>  static void *qcom_swrm_get_sdw_stream(struct snd_soc_dai *dai, int direction)
>  {
>  	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
> @@ -1349,7 +1339,6 @@ static const struct snd_soc_dai_ops qcom_swrm_pdm_dai_ops = {
>  	.hw_free = qcom_swrm_hw_free,
>  	.startup = qcom_swrm_startup,
>  	.shutdown = qcom_swrm_shutdown,
> -	.set_stream = qcom_swrm_set_sdw_stream,
>  	.get_stream = qcom_swrm_get_sdw_stream,
>  };
>