Yeah. There was an attempt to upstream that driver (by someone not involved in it), and the need for a better userspace API for backlight control got mentioned,

Yeah. There was an attempt to upstream that driver (by someone not involved in it), and the need for a better userspace API for backlight control got mentioned, so the driver wasn't merged. Probably a better driver will get merged eventually. https://lore.kernel.org/all/7f2d88de-60c5-e2ff-9b22-acba35cfdfb6@redhat.com/ https://lore.kernel.org/all/7f2d88de-60c5-e2ff-9b22-acba35cf...