Hi!
I have been learning how to use NixOS for a couple weeks now, however, I ran into an issue I can’t quite figure out. I have an LSK Meeting Eye webcam. It worked flawlessly under OpenSUSE Tumbleweed. On NixOS, it shows up in lsusb, and even /dev/media0 gets created, but no video device is available. Interestingly, if I plug in a different usb webcam, that one seems to function as intended. I can’t seem to find any documentation or previous discussions related to this.
My current configuration: nixos-config/flake.nix at e8622536627c2577d0251766056ea42cba8c29c4 - lilymeow/nixos-config - git.gay
Here are some outputs that might be useful:
v4l2-ctl --list-devices:
LSK Meeting Eye for Business & (usb-0000:00:14.0-1):
/dev/media0
Cannot open device /dev/video0, exiting.
dmesg:
[ 1777.168712] uvcvideo 1-1:1.0: Found multiple Units with ID 4
[ 1777.168736] usb 1-1: Found UVC 1.00 device LSK Meeting Eye for Business & Home (1d6b:0105)
[ 1777.180144] usb 1-1: No streaming interface found for terminal 65535.
[ 1777.180558] usbcore: registered new interface driver uvcvideo
lsusb -v: https://cryptpad.fr/pad/#/2/pad/view/smHYbrf3mzEX36eg5KZf1NdxDqF6PGMI40VhB5726zI/ (couldn’t fit into the text body)
I’d first try sudo v4l2-ctl --list-devices to rule out permission issues. Assuming that also fails, I’d compare kernel versions between Tumbleweed and your current NixOS system, and see if upgrading/downgrading it works.
Unfortunately that’s not it. I tried both linux 6.16 and latest, but it’s the same result in both cases - even with sudo.
Update: I’ve tried to build a custom kernel by getting the diff between the NixOS and OpenSUSE kernel configs and applying them to the NixOS one, I did succeed in building one with only all the usb and video related options copied, but I keep running into issues when trying to copy all options, and I don’t really want to dig through over 1000 lines to see which ones are causing it (each execution takes 1-2 minutes to see if it will fail). I don’t think it would really make that much of a difference anyway. Even with the first custom built kernel, I still get the same output.
New clue: the webcam works when booting from the installation media. I was quick to assume that it’s because of the hardware.enableAllHardware = true setting, but I tried setting that in my own one and still nothing.
Maybe try hardware.enableAllFirmware = true? I don’t think there’s anything relevant there but just in case it’s worth a try
I figured it out. The issue is a regression in the kernel created by this commit, so I had to create a patch to revert that change.
Here’s the patch if anyone is having the same problem: nixos-config/jupiter/kernel/webcam-fix.patch at 11bb710ec9c6fe666c58112e2b27e946453326ca - lilymeow/nixos-config - git.gay
I’ll try to report this to the linux project, though I’ve never done that before.
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Building with your patch just fixed my issue! (I have some off brand webcams that used to work but stopped.) Was just about to give up on it. Thank you!
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I’m glad it was useful! When I reported the issue to the kernel maintainers they actually sent me a patch which solves the issue differently, but this should be fine until that gets merged if you don’t want to recompile again.
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ah right - I see it in your repo - i’ll probably try it soon but great to have one I know works
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