Hello, I have the same problem after upgrading QNAP TS419pII from Jessie to Strech.
After restarting whole system there is no "/sys/class/gpio/gpio45/" directory, so as suggested, I've tried: echo 45 > /sys/class/gpio/export and restarted qcontrold and qcontrol - LCD controls are back. Overall, there seems to be a problem with qcontrold/qcontrol on Stretch or kernel 4.9, this is what I observed: 1. qcontrold/qcontrol is not starting properly (related to https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=852127) 2. LCD is not working after booting up (this bug) 3. Power button is not working - it just restarts device, I've also noticed that even LCD backlight is turned off by default, after restart is on. Linux QNAP-TS419 4.9.0-1-marvell #1 Debian 4.9.6-3 (2017-01-28) armv5tel GNU/Linux Thank you, Best Regards, Marek
