Brightness randomly up and down on MSI laptop

Solution 1:

This seems to be a common problem on most MSI laptops, including my own GP62 6QF Leopard Pro. Supposedly, one way to fix it would be to update your BIOS, however, this didn't work for me.

I managed to fix this by adding this to /usr/share/X11/xorg.conf.d/10-quirks.conf:

  Section "InputClass"
  Identifier "Spooky Ghosts"
  MatchProduct "Video Bus"
  Option "Ignore" "on"
  EndSection

This basically ignores messages from the Video Bus, which seems to be sending psuedo fn+up fn+down messages randomly.

Source: https://ubuntuforums.org/showthread.php?t=2314161&page=2

EDIT: Note that this is not a permanent fix as 10-quirks.conf is a file frequently overwritten by OS updates. The most recent update at this time of writing, released on the 7th of August, had overwritten this file and the above-mentioned script was not retained. To fix it back again, you'll just have to type it back in again, or submit a bug report informing them about this fix.

FYI, the 10-quirks.conf file is used for exactly this cause -- to fix bugs caused by hardware incompatibilities.