Yu Watanabe

@jwrdegoede 'Fix' is waiting in #24998.

Ugh, I found another bug. Please backport the first commit.

#24801 is merged. Please rebase this PR if still relevant.

Please create new one.

Ubuntu CIs are quite unstable. Please simply ignore the failures if they seem unrelated.

I do not have affected laptops, so I cannot follow the discussions. But feel free to open any follow-up PRs. Thank you.

Closing, as the commit is included in #22694.

Could you show the result of `udevadm info --tree /sys/class/backlight/amdgpu_bl0` and `/sys/class/backlight/nvidia_wmi_ec_backlight` (and also other devices if there exist other backlight devices in /sys/class/backlight)?

Thanks. Could you also show the results of `udevadm info --attribute-walk` for these backlight devices?

Thank you!