Package: xbacklight Version: 1.2.1-1 Followup-For: Bug #833508 same problem here, came unexpectedly after settting brightness to zero, then couldn't light up the screen. a reboot (I tried killing X but it wouldn't launch again) put the screen at 100% and I was not able to get it down with xbacklight - had to write the sys files so I could keep using the laptop.
this is the last system update I did yesterday: http://www.pastebin.ca/3705482 as you can see, there were no xorg or kernel-related updates (nor were there in the previous update a week ago). I can confirm that forcing it to use the "intel" driver via xorg.conf (what Debianer <o...@bluemonk.de> suggested), makes it work again. the relevant packages are: # aptitude versions xserver-xorg-video-intel Package xserver-xorg-video-intel: p 2:2.21.15-2+b2 stable 500 p 2:2.99.917+git20160522-1~bpo8+1 jessie-backports 100 i 2:2.99.917+git20160706-1 testing,unstable 600 # aptitude versions xserver-xorg-core Package xserver-xorg-core: p A 2:1.16.4-1 stable 500 i A 2:1.18.4-1 testing,unstable 600 -- System Information: Debian Release: stretch/sid APT prefers testing APT policy: (600, 'testing'), (500, 'stable'), (400, 'unstable'), (1, 'experimental') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.6.0-1-amd64 (SMP w/4 CPU cores) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages xbacklight depends on: ii libc6 2.23-4 ii libxcb-randr0 1.11.1-1.1 ii libxcb-util0 0.3.8-3 ii libxcb1 1.11.1-1.1 xbacklight recommends no packages. xbacklight suggests no packages. -- debconf-show failed
