Re: [PATCH 3/3] ASoC: codecs: wsa884x: check if set_stream is called for proper bus

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

On 10/25/23 09:46, Krzysztof Kozlowski wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> 
> If multiple WSA8840 speakers, from two separate Soundwire buses, are
> used in one codec DAI link, the set_stream() should ignore calls for
> setting stream from other Soundwire controller.
> 
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Co-developed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
>  sound/soc/codecs/wsa884x.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/sound/soc/codecs/wsa884x.c b/sound/soc/codecs/wsa884x.c
> index bee6e763c700..91205e8c96f1 100644
> --- a/sound/soc/codecs/wsa884x.c
> +++ b/sound/soc/codecs/wsa884x.c
> @@ -1775,6 +1775,12 @@ static int wsa884x_set_stream(struct snd_soc_dai *dai,
>  			      void *stream, int direction)
>  {
>  	struct wsa884x_priv *wsa884x = dev_get_drvdata(dai->dev);
> +	struct sdw_stream_runtime *sruntime = stream;
> +	struct sdw_slave *sdw = dev_to_sdw_dev(dai->dev);
> +
> +	/* Check if this belongs to same bus */
> +	if (sdw->bus->dev != sruntime->dev)
> +		return 0;

Sorry, maybe I am really thick or need coffee, but I can't figure out
why this is necessary. Each amplifier has its own "wsa884x_priv" context
and should have its own DAI, not following why the set_stream would
mix-up the two dais?

We've been using two buses for two amplifiers since CometLake (2019?)
and I don't see what's different?

>  
>  	wsa884x->sruntime = stream;
>