https://bugs.freedesktop.org/show_bug.cgi?id=81382
--- Comment #10 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #7)
Ok, this fix work, but cause another problem (tested with 3.15.5+patch and 3.16.1).
When display goes off, backlight goes off. When display goes on, backlight is set to MAX. When display goes off again, backligh remains MAX. After pressing key, LCD works, backlight stay at MAX level. When display goes off, backlight is still MAX.
Does the backlight respond correctly when adjusted via the sysfs blacklight interface?