USB Audio 2.0 - how to provide host with a range or list of supported sample frequencies ?

[paulw2]

Hello,

In UAC 2, how should the MCU audio device provide the host with a list of supported sample rates ?

Using SDK 2.16 dev_audio_speaker_freertos example on i.MXRT1010 evaluation board.

In this example, is it correct that for UAC2 the supported sample rates are provided to the host via audio_speaker.c:USB_DeviceAudioRequest() returning freqControlRange for the GET_RANGE_SAMPLING_FREQ_CONTROL case ?

Modifying audio_speaker.c:g_UsbDeviceAudioSpeaker.freqControlRange does not produce the expected results :-

/* wNumSubRanges, wMIN, wMAX, wRES */

.freqControlRange = {1U, 48000U, 48000U, 0U} - host lists 48kHz - original values

.freqControlRange = {1U, 44100U, 48000U, 0U} - host lists 44.1kHz + 48kHz

.freqControlRange = {1U, 44100U, 96000U, 0U} - host lists 44,1kHz - expected a range 44.1kHz, 48kHz, 88.2kHz and 96kHz

What am I missing ?

Thanks.