[RPi4] USB DAC disconnects

    I have been having issues with my USB DAC and found this in DMESG. LibreELEC (official): 12.2.1

    Any ideas why it is disconnecting? I was thinking maybe a power issue but:

    vcgencmd get_throttled
    throttled=0x0

    So no undervolts and I am using a good original Raspberry Pi 4 power supply.


    [ 91.758264] usb 1-1.2: new full-speed USB device number 3 using xhci_hcd
    [ 91.854913] usb 1-1.2: New USB device found, idVendor=0d8c, idProduct=0012, bcdDevice= 1.00
    [ 91.854943] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
    [ 91.854954] usb 1-1.2: Product: USB Audio Device
    [ 91.854963] usb 1-1.2: Manufacturer: C-Media Electronics Inc.
    [ 91.865704] input: C-Media Electronics Inc. USB Audio Device as /devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1
    -1.2/1-1.2:1.3/0003:0D8C:0012.0001/input/input2
    [ 91.918680] hid-generic 0003:0D8C:0012.0001: input,hidraw0: USB HID v1.00 Device [C-Media Electronics Inc. USB Audio Device] on usb-0000:01:00.0-1.
    2/input3
    [ 92.046382] usbcore: registered new interface driver snd-usb-audio
    [ 93.230156] usb 1-1.2: USB disconnect, device number 3

    Edited once, last by duncang92: adding info re power and throttling check (July 20, 2026 at 10:44 PM).

    As the DAC uses generic usb-audio drivers used by tens of millions of devices, it's probably NOT a driver problem.

    Two suggestions (test them separately):

    a) If the device is connected to a USB 3.0 port, move it to a USB 2.0 port (some CMedia devices prefer 2.0)

    b) See if adding usbcore.autosuspend=-1 to kernel params in cmdline.txt changes the behaviour

    Quote from chewitt

    As the DAC uses generic usb-audio drivers used by tens of millions of devices, it's probably NOT a driver problem.

    Two suggestions (test them separately):

    a) If the device is connected to a USB 3.0 port, move it to a USB 2.0 port (some CMedia devices prefer 2.0)

    i moved it from the USB 3.0 port and it showed up with lsusb ..... I then rebooted the Pi and lsusb doesn't show it.

    Quote from chewitt

    b) See if adding usbcore.autosuspend=-1 to kernel params in cmdline.txt changes the behaviour

    I added the param and lsusb still doesn't show it


    I think my next step will be to do a clean new install and start afresh

    Quote from Da Flex

    duncang92 Which USB DAC do you have? It's not visible in your log snippet.

    Other than it telliing me it is a C-Media product I do not know as there is nothing written on it

    Edited once, last by duncang92: Merged a post created by duncang92 into this post. (July 22, 2026 at 4:15 PM).

    Quote from chewitt

    Most odd. Does the device show up again when reconnected to the USB 3.0 port (with autosuspend=-1 set)?

    Well yes it did. Then after reboot it was gone again.

    I decided to see what happens with all the USB ports and nothing. I did notice that sometimes the display (1080p TV on HDMI) will go off when unplugging which seems mightily odd and then once a reboot for no apparent reason.

    I am starting to think something is corrupted in my install as it seems CEC has now decided not to work.

    It's not really possible to corrupt the core OS as LE packages kernel and userspace into two squashfs files that are expanded on boot into a virtual read-only filesystem. If you corrupt either file on the SD card they fail to decompress and the OS fails to boot. Once the OS has booted; 99% of important things are read-only. For kicks please experiment with the latest LE13 nightly on a spare SD card; it has newer kernel/drivers than LE12.2.

    Quote from duncang92

    I am starting to think something is corrupted in my install as it seems CEC has now decided not to work.

    Please provide a full debug log.

    How to post a log (wiki)

    1. Enable debugging in Settings>System Settings>Logging
    2. Restart Kodi
    3. Replicate the problem
    4. Generate a log URL (do not post/upload logs to the forum)

    use "Settings > LibreELEC > System > Paste system logs" or run "pastekodi" over SSH, then post the URL link