I have a device that combines two audio interfaces and one HID interface.
It enumerates correctly, as
lsusb -D shows. Also, a trace with
wireshark shows no errors - all descriptors are exchanged successfully,
Set Interface requests are issued by the host and are acknowledged by the device.
dmesg also does not complain:
sw3@pc90313-sw3:~$ dmesg | tail [ 6897.106331] input: Logitech USB Optical Mouse as /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.3/1-1.3:1.0/input/input14 [ 6897.106516] hid-generic 0003:046D:C05A.0007: input,hidraw0: USB HID v1.11 Mouse [Logitech USB Optical Mouse] on usb-0000:00:1a.0-1.3/input0 [ 6902.395444] usb 3-1: new high-speed USB device number 45 using xhci_hcd [ 6902.413395] usb 3-1: New USB device found, idVendor=23e5, idProduct=a050 [ 6902.413400] usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 6902.413403] usb 3-1: Product: Device [ 6902.413405] usb 3-1: Manufacturer: Me [ 6902.417288] current rate 44100 is different from the runtime rate 192000 [ 6902.420775] current rate 44100 is different from the runtime rate 192000 [ 6902.424214] hid-generic 0003:23E5:A050.0008: hiddev0,hidraw3: USB HID v1.11 Device [My Device] on usb-0000:00:14.0-1/input3
Yet the device does not appear in the Sound menu in the configuration panel of Ubuntu. My reasoning is, if the configuration descriptor was wrong, and the host didn't know that the device is an audio device, there wouldn't be
Set interface requests (those serve for muting and unmuting).
I want to dig deeper and find out where in the chain is the device not recognised as an audio device. However, my Linux knowledge is meager and I do not know which logs to read, which utilities to use and how to circumvent "Sound" menu on the next lower level of abstraction.
What is the process of adding a device to the Sound menu and at what points can it be observed?