libcomposite UAC2 gadget starts; doesn't appear on connected devices

[etzabo]

In my travels, I've decided to undertake the task of making my own car stereo, but alas: the UAC2 device I attempt to create through libcomposite does not register with devices I connect through any of my 4B's USB ports! Even dmesg taunts me with the USB driver binding and recognition of a connected device:

Code: [Select]

$ dmesg
... # See full dmesg output attached.
[  135.025020] dwc2 fe980000.usb: bound driver configfs-gadget.tacobox-audio
[  163.228186] usb 2-2: new SuperSpeed USB device number 2 using xhci_hcd
[  163.251162] usb 2-2: New USB device found, idVendor=05ac, idProduct=1905, bcdDevice=15.06
[  163.251181] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  163.251194] usb 2-2: Product: Mac
[  163.251204] usb 2-2: Manufacturer: Apple Inc.
[  163.251213] usb 2-2: SerialNumber: HDJW1R39KK
This is quite confusing! How does the system register a gadget, query a USB connection, but never present itself as a UAC2 device? I even see the gadget appear as a capture device from piCore:

Code: [Select]

$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: UAC2Gadget [UAC2_Gadget], device 0: UAC2 PCM [UAC2 PCM]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

My process is as follows:

• Load custom kernel module extension "uac2-mods.tcz" (contains all "sound" and "drivers/usb" modules)
• Run attached script "uac2.sh" as root

What's the matter? I look online to see numerous guides that do the same as I do, yet they never face this issue. I assume the cause to be some nuance brought upon by Tiny Core, but I don't see any fatal errors or warnings when running these commands.