Re: [RFC PATCH v2 6/6] ASoC: q6asm-dai: add support to set_codec_params

[Pierre-Louis Bossart]

On 7/21/20 12:00 PM, Srinivas Kandagatla wrote:
> Make use of new set_codec_params callback to allow decoder switching
> during gapless playback.
>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
>   sound/soc/qcom/qdsp6/q6asm-dai.c | 33 ++++++++++++++++++++++++++++++++
>   1 file changed, 33 insertions(+)
>
> diff --git a/sound/soc/qcom/qdsp6/q6asm-dai.c b/sound/soc/qcom/qdsp6/q6asm-dai.c
> index b5c719682919..a8cfb1996614 100644
> --- a/sound/soc/qcom/qdsp6/q6asm-dai.c
> +++ b/sound/soc/qcom/qdsp6/q6asm-dai.c
> @@ -876,6 +876,37 @@ static int __q6asm_dai_compr_set_codec_params(struct snd_soc_component *componen
>   	return 0;
>   }
>   
> +static int q6asm_dai_compr_set_codec_params(struct snd_soc_component *component,
> +					    struct snd_compr_stream *stream,
> +					    struct snd_codec *codec)
> +{
> +	struct snd_compr_runtime *runtime = stream->runtime;
> +	struct q6asm_dai_rtd *prtd = runtime->private_data;
> +	int ret;
> +
> +	ret = q6asm_open_write(prtd->audio_client, prtd->next_track_stream_id,
> +			       codec->id, codec->profile, prtd->bits_per_sample,
> +			       true);
> +	if (ret < 0) {
> +		pr_err("q6asm_open_write failed\n");
> +		return ret;
> +	}
> +
> +	ret = __q6asm_dai_compr_set_codec_params(component, stream, codec,
> +						 prtd->next_track_stream_id);
> +	if (ret < 0) {
> +		pr_err("q6asm_open_write failed\n");
> +		return ret;
> +	}
> +
> +	ret = q6asm_stream_remove_initial_silence(prtd->audio_client,
> +						   prtd->next_track_stream_id,
> +						   prtd->initial_samples_drop);
> +	prtd->next_track_stream_id = 0;

same comment as in the other patchset, the stream_id toggles between 1 
and 2, it's not clear to me what 0 means.

off-by-one bug or feature?