ACPI backlight error

System … HefftorLinux rolling
▉▉| Packages … 1186 (pacman)
▉▉ | Uptime … 2h 25m
▉▉| Resolution … 1366x768
▉▉ |
▉▉| WM … Xfwm4
▉▉ | Shell … bash 5.1.4
▉▉| Terminal … xfce4-terminal
▉▉ | Term Font … Source Code Pro 10
▉▉|
▉▉ | Kernel … 5.12.1-zen2-1-zen
▉▉| Processor … Ryzen 5 2500U with Radeon Vega Mobile Gfx (8C) [45.0°C]
▉▉ | Gpu … ATI Radeon R7 M260/M265
▉▉|
▉▉ | Disk … 13G / 110G (13%) (ext4)
▉▉|
▉▉ | Birthday …
▉▉| Memory … 1225MiB / 22997MiB

~
:: systemctl --failed
UNIT LOAD ACTIVE SUB DESCRIPT>
● systemd-backlight@backlight:acpi_video0.service loaded failed failed Load/Sav>
● systemd-backlight@backlight:acpi_video1.service loaded failed failed Load/Sav>

LOAD = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB = The low-level unit activation state, values depend on unit type.
2 loaded units listed.
lines 1-8/8 (END)

Hello guys, Anyone knows how to solve this? thanks a lot!

you could try adding acpi_backlight=vendor to the grub default line

/etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_backlight=vendor"

I wonder why, when problems arise, users don’t research Arch Linux and Arch Wiki first.

Thanks Brad, the kernel still shows the errors but the brightness is working, thanks a lot!!!