Re: [PATCH 1/2] ASoC: wcd9335: fix order of Slimbus unprepare/disable

[Pierre-Louis Bossart]

On 9/21/22 16:53, Krzysztof Kozlowski wrote:
> Slimbus streams are first prepared and then enabled, so the cleanup path
> should reverse it.  The unprepare sets stream->num_ports to 0 and frees
> the stream->ports.  Calling disable after unprepare was not really
> effective (channels was not deactivated) and could lead to further
> issues due to making transfers on unprepared stream.
> 
> Fixes: 20aedafdf492 ("ASoC: wcd9335: add support to wcd9335 codec")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> ---
>  sound/soc/codecs/wcd9335.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sound/soc/codecs/wcd9335.c b/sound/soc/codecs/wcd9335.c
> index 06c6adbe5920..d2548fdf9ae5 100644
> --- a/sound/soc/codecs/wcd9335.c
> +++ b/sound/soc/codecs/wcd9335.c
> @@ -1972,8 +1972,8 @@ static int wcd9335_trigger(struct snd_pcm_substream *substream, int cmd,
>  	case SNDRV_PCM_TRIGGER_STOP:
>  	case SNDRV_PCM_TRIGGER_SUSPEND:
>  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
> -		slim_stream_unprepare(dai_data->sruntime);
>  		slim_stream_disable(dai_data->sruntime);
> +		slim_stream_unprepare(dai_data->sruntime);

This looks logical but different from what the kernel doc says:

/**
 * slim_stream_disable() - Disable a SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to disable
 *
 * This API will disable all the ports and channels associated with
 * SLIMbus stream
 *
 * Return: zero on success and error code on failure. From ASoC DPCM
framework,
 * this state is linked to trigger() pause operation.
 */

/**
 * slim_stream_unprepare() - Un-prepare a SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to unprepare
 *
 * This API will un allocate all the ports and channels associated with
 * SLIMbus stream
 *
 * Return: zero on success and error code on failure. From ASoC DPCM
framework,
 * this state is linked to trigger() stop operation.
 */

I would bet the documentation is incorrect?

>  		break;
>  	default:
>  		break;