I tried acpi_backlight=vendor on grub to novail. It even stopped working on the TTY. Putting grub as it was restored the functionality back in the TTY. Under X11, the problem persists.
I tried acpi_backlight= vendor on grub to novail. It even stopped working on the TTY. Putting grub as it was restored the functionality back in the TTY. Under X11, the problem persists.