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cherry-embedded / CherryUSB

CherryUSB is a tiny and portable USB Stack (device & host) for embedded system with USB IP
https://cherryusb.readthedocs.io/
Apache License 2.0
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USB HS Device : UAC2 issues #149

Closed OpusElectronics closed 8 months ago

OpusElectronics commented 8 months ago

Hello,

I've been testing CherryUSB on a CH32V307 and it looks great. Having issues with the audio class though. I've tested the following:

audio_v2_mic_speaker_multichan_template.c

There is no audio example yet on the following repo: https://github.com/CherryUSB/cherryusb_wch , but following other examples, I have set up a project with the above demo template. The USB device is correctly recognized as a UAC2 device with the corresponding bit format and sample rates defined in the audio_v2_mic_speaker_multichan_template.c code. So, that's encouraging. :)

The part that doesn't work properly though is once we start streaming audio from/to the device. On Linux (tested on 2 different machines, same problem), we get a lot of the following kind of error in dmesg:

retire_capture_urb: 18822 callbacks suppressed

My guess is that in the usbd_audio_iso_out_callback() and/or usbd_audio_iso_in_callback(), we are not sending/receiving the appropriate number of bytes.

In the demo code, you call: usbd_ep_start_read(AUDIO_OUT_EP, read_buffer, AUDIO_OUT_PACKET); in usbd_audio_iso_out_callback(). I've tried changing AUDIO_OUT_PACKET to nbytes, but it doesn't change much. I've also tried adding the following line in usbd_audio_iso_in_callback()

usbd_ep_start_write(AUDIO_IN_EP, write_buffer, AUDIO_IN_PACKET);

(in your demo code, it's empty), but it doesn't solve the issue either.

There's probably something I've overlooked - could you help with this audio class? That would be great.

sakumisu commented 8 months ago

Audio does not support on all ch32 chips because with no iso driver( you can ask official for help), thanks.

sakumisu commented 8 months ago

You can try other chips like hpm or bouffalolab.

OpusElectronics commented 8 months ago

Thanks. So audio can't work as isochronous transfers are not currently supported in CherryUSB for the CH32 chips? Is this planned in the future?

sakumisu commented 8 months ago

Thanks. So audio can't work as isochronous transfers are not currently supported in CherryUSB for the CH32 chips? Is this planned in the future?

No plan. I do not want to guess iso drivers with official registers without reference.

sakumisu commented 8 months ago

You can refer to this :https://github.com/nikkov/AudioCardCherry

OpusElectronics commented 8 months ago

Thanks, I will.