The brightness interface (/sys/class/backlight/intel_backlight) is working, so it must be the missing events that cause your problem.
Ubuntu needs keycodes (KEY_BRIGHTNESSDOWN 224 & KEY_BRIGHTNESSUP 225), and this can be from either scancode or ACPI events. Laptops usually use ACPI for brightness, and this can be confirmed by pressing hotkeys while running $ watch -n1 cat /proc/interrupts Note: ACPI usually is on IRQ 9. Check whether interrupts increase with brightness up/down presses. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1872311 Title: Brightness hotkeys not working on Lenovo S740 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1872311/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
