Decided to uninstall my display manager and use startx instead. But now when I resume from suspend, the brightness keys cease to work until I log out and back in. Backlight does still respond when echoing into /sys/class/backlight/intel_backlight/brightness. But what kind of magic does a display manager do to keep brightness controls working after suspend and resume?
Using xfce on tty1 on an X230 if it matters.
My 2012 MacBook Pro has exactly the opposite behaviour on a clean install across multiple distros. The brightness keys do nothing until after a suspend, then work fine until the next reboot. Never found a fix.