Re: [REGRESSION] usb-audio: Behringer UMC204HD broken in 7.2.10

[Takashi Iwai <tiwai@suse.de>]

On Sun, 18 Oct 2026 18:34:27 +0200,
Will Bush wrote:
> 
> Hi Takashi,
> 
> Thanks for all your work on usb-audio. I was updating my system (NixOS), which
> took me from 7.2.9 to 7.2.10, and my Behringer UMC204HD device stopped working.
> 
> It gets into a loop:
> 
>   [  225.148019] blazar kernel: usb 3-4: new high-speed USB device number 19 using xhci_hcd
>   [  225.340016] blazar kernel: usb 3-4: New USB device found, idVendor=1397, idProduct=0508, bcdDevice= 1.35
>   [  225.366005] blazar kernel: usb 3-4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
>   [  225.366187] blazar kernel: usb 3-4: Product: UMC204HD 192k
>   [  225.366304] blazar kernel: usb 3-4: Manufacturer: BEHRINGER
>   [  230.493021] blazar kernel: usb 3-4: failed to read device descriptor: -110
>   [  230.493313] blazar kernel: snd-usb-audio 3-4:1.0: probe with driver snd-usb-audio failed with error -110
>   [  235.612029] blazar kernel: usb 3-4: failed to read device descriptor: -110
>   [  235.612302] blazar kernel: snd-usb-audio 3-4:1.3: probe with driver snd-usb-audio failed with error -110
>   [  240.732035] blazar kernel: usb 3-4: failed to read device descriptor: -110
>   [  240.732461] blazar kernel: snd-usb-audio 3-4:1.4: probe with driver snd-usb-audio failed with error -110
>   [  240.732538] blazar kernel: usb 3-4: USB disconnect, device number 19
>   [  241.019061] blazar kernel: usb 3-4: new high-speed USB device number 20 using xhci_hcd
> 
> Issue seems to be from commit: b5c4823cf3e4 ("ALSA: usb-audio: Apply boot quirk for Behringer models generically")
> 
> I was able to patch 7.2.10 to get it working again:
> 
> -	if (USB_ID_VENDOR(id) == 0x1397)
> +	if (id == USB_ID(0x1397, 0x1234))
> 
> Not sure if applying the quirk to every Behringer device is too broad or what
> the fix should be. Ping me if you want me to test a patch.
> 
> #regzbot introduced: b5c4823cf3e4

Interesting, it's just a descriptor read and this fails on your device
by some reason.  Could you try to ignore the error like below, and
verify whether it continues to work?


thanks,

Takashi

--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -865,7 +865,7 @@ static int snd_usb_cm1a_boot_quirk(struct usb_device *dev)
 	err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, sizeof(*desc));
 	if (err < 0) {
 		dev_err(&dev->dev, "failed to read device descriptor: %d\n", err);
-		return err;
+		// return err;
 	}
 
 	return 0;