Re: [PATCH v2] ASoC: bdw-rt5650: remove 3-channel capture support

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

On 4/13/20 3:28 AM, Brent Lu wrote:
> Implement a constrain to exclude 3-channel capture since only 2 and 4
> channel capture are supported on the platform.

That looks like an error caught by the ALSA conformance tool?

What are the odds that we have a similar issue with the other broadwell 
drivers which don't have a constraint on the number of channels either 
on their 'System PCM' dailink?

Thanks
-Pierre

> 
> Signed-off-by: Brent Lu <brent.lu@intel.com>
> ---
>   sound/soc/intel/boards/bdw-rt5650.c | 31 +++++++++++++++++++++++++++++++
>   1 file changed, 31 insertions(+)
> 
> diff --git a/sound/soc/intel/boards/bdw-rt5650.c b/sound/soc/intel/boards/bdw-rt5650.c
> index af2f502..eedbdad 100644
> --- a/sound/soc/intel/boards/bdw-rt5650.c
> +++ b/sound/soc/intel/boards/bdw-rt5650.c
> @@ -83,6 +83,36 @@ static struct snd_soc_jack_pin mic_jack_pin = {
>   	.mask	= SND_JACK_MICROPHONE,
>   };
>   
> +static const unsigned int channels[] = {
> +	2, 4,
> +};
> +
> +static const struct snd_pcm_hw_constraint_list constraints_channels = {
> +	.count = ARRAY_SIZE(channels),
> +	.list = channels,
> +	.mask = 0,
> +};
> +
> +static int bdw_fe_startup(struct snd_pcm_substream *substream)
> +{
> +	struct snd_pcm_runtime *runtime = substream->runtime;
> +
> +	/*
> +	 * On this platform for PCM device we support,
> +	 * 2 or 4 channel capture
> +	 */
> +	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
> +		snd_pcm_hw_constraint_list(runtime, 0,
> +					   SNDRV_PCM_HW_PARAM_CHANNELS,
> +					   &constraints_channels);
> +
> +	return 0;
> +}
> +
> +static const struct snd_soc_ops bdw_rt5650_fe_ops = {
> +	.startup = bdw_fe_startup,
> +};
> +
>   static int broadwell_ssp0_fixup(struct snd_soc_pcm_runtime *rtd,
>   			struct snd_pcm_hw_params *params)
>   {
> @@ -234,6 +264,7 @@ static struct snd_soc_dai_link bdw_rt5650_dais[] = {
>   		.name = "System PCM",
>   		.stream_name = "System Playback",
>   		.dynamic = 1,
> +		.ops = &bdw_rt5650_fe_ops,
>   #if !IS_ENABLED(CONFIG_SND_SOC_SOF_BROADWELL)
>   		.init = bdw_rt5650_rtd_init,
>   #endif
>