Re: [PATCH v24 15/34] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

Pierre-Louis Bossart
2024-08-01T09:30:41Z

On 8/1/24 03:17, Wesley Cheng wrote:
> The QC ADSP is able to support USB playback endpoints, so that the main
> application processor can be placed into lower CPU power modes. This adds
> the required AFE port configurations and port start command to start an
> audio session.
>
> Specifically, the QC ADSP can support all potential endpoints that are
> exposed by the audio data interface. This includes, feedback endpoints
> (both implicit and explicit) as well as the isochronous (data) endpoints.
> The size of audio samples sent per USB frame (microframe) will be adjusted
> based on information received on the feedback endpoint.
>
> Some pre-requisites are needed before issuing the AFE port start command,
> such as setting the USB AFE dev_token. This carries information about the
> available USB SND cards and PCM devices that have been discovered on the
> USB bus. The dev_token field is used by the audio DSP to notify the USB
> offload driver of which card and PCM index to enable playback on.

It's just fine if the AFE stuff relies on the 'port' definition/concept,
but I don't think it needs to pop-up at the ASoC/USB level.