Kernel 5.15.5+ names all video devices "Video Capture X"

[HikariKnight]

Distribution (run cat /etc/os-release):

NAME="Pop!_OS"
VERSION="21.04"
ID=pop
ID_LIKE="ubuntu debian"
PRETTY_NAME="Pop!_OS 21.04"
VERSION_ID="21.04"
HOME_URL="https://pop.system76.com"
SUPPORT_URL="https://support.system76.com"
BUG_REPORT_URL="https://github.com/pop-os/pop/issues"
PRIVACY_POLICY_URL="https://system76.com/privacy"
VERSION_CODENAME=hirsute
UBUNTU_CODENAME=hirsute
LOGO=distributor-logo-pop-os

Related Application and/or Package Version (run apt policy $PACKAGE NAME):

linux-image-5.15.5-76051505-generic:
  Installed: 5.15.5-76051505.202111250933~1638201579~21.04~09f1aa7
  Candidate: 5.15.5-76051505.202111250933~1638201579~21.04~09f1aa7
  Version table:
 *** 5.15.5-76051505.202111250933~1638201579~21.04~09f1aa7 1001
       1001 http://ppa.launchpad.net/system76/pop/ubuntu hirsute/main amd64 Packages
        100 /var/lib/dpkg/status
linux-modules-5.15.5-76051505-generic:
  Installed: 5.15.5-76051505.202111250933~1638201579~21.04~09f1aa7
  Candidate: 5.15.5-76051505.202111250933~1638201579~21.04~09f1aa7
  Version table:
 *** 5.15.5-76051505.202111250933~1638201579~21.04~09f1aa7 1001
       1001 http://ppa.launchpad.net/system76/pop/ubuntu hirsute/main amd64 Packages
        100 /var/lib/dpkg/status

Issue/Bug Description:
The newest kernel seems to rename all webcam/video peripherals to "Video Capture X", the name is not given sequentially and is the same number across devices.
As an example my Elgato Camlink 4K and Trust HD Webcam gets renamed to "Video Capture 3" while my Avermedia LGP2 gets renamed to "Video Capture 4" on any computer with pop os it gets connected to.

I suspect the kernels built in video4linux2 module for some reason sets the ID_V4L_PRODUCT value to "Video Capture X" instead of the name of the device (ID_MODEL?)

Steps to reproduce (if you know):
Update to Kernel 5.15.5-76051505 and reboot to use it.
Switching back to the older kernel will fix the device names again.

Expected behavior:
Video devices to be named normally like this

and not like this

Other Notes:
I had a laptop that was not fully updated yet and updated everything except the kernel packages and rebooted to see if it was a kernel problem or not before taking the pictures, it turned out to only happen in the new kernel and not the old kernel when i tested.

To make the issue worse, the kernel seems to not dynamically create the names "Video Capture 1", "Video Capture 2", etc.
The name seems to be hard coded for the devices as several devices will appear as "Video Capture 3" for instance on my desktop computer which has multiple cameras connected.

Example image from discord, showing how confusing it will look for the end user to select the "correct" device to use

Hopefully this will be enough info to get this corrected 😃

[jacobgkau]

What motherboard are you using?

Hopefully this will be enough info to get this corrected 😃

Does the issue also occur on other distributions running the 5.15.5 kernel, or do you have reason to believe this is being caused by Pop!_OS patches to the kernel?

[HikariKnight]

I am in the middle of testing this actually, it is just that all my devices are running pop os, so i had to spend time downloading some extra distributions to test with.
and i know it is not a motherboard related issue since it happens on 3 laptops and 2 desktops.
however my main machines motherboard is an ASUS Prime X399-A

[HikariKnight]

Downloaded a few other distros (arch and fedora) and installed the 5.15.5 kernel (and 5.15.6 on arch) and it seems the issue is upstream and not related to the system76 patches to the kernel

[jacobgkau]

Thank you for confirming that. We can keep the issue open here for tracking, but it probably needs to be addressed upstream.

Searching around a bit, I found one patch that looked like it may have caused this change in 5.15: https://www.spinics.net/lists/kernel/msg4136129.html

[HikariKnight]

Good idea to keep it for tracking as when i was searching around to see if others had the issue, i could really not find any results related to this in general.
This way if someone comes here from lets say google, they can see it is an upstream issue.

EDIT: Seems like the kernel developers have been made aware of the regression already
https://www.spinics.net/lists/linux-media/msg203735.html

[ozdreamern]

It looks like this will be fixed/reverted in 5.15.15 (see patch for more detail).

[HikariKnight]

Can confirm that 5.15.15 fixes it, however it doubles the name for some devices (those previously named Video Capture 3 from the regression), but i will take this any day over having everything named "Video Capture X" 😄

[HikariKnight]

kernel 5.15.15 is now out for pop so i think this can now be closed.