May be the community is looking for the solution in the wrong direction. Looking in /sys/class/backlight/ lists 3 folders on my Dell inspiron 7520. One of the folders is intel_backlight .
Manually doing root@Sirius:~# echo 2000 > /sys/class/backlight/intel_backlight/brightness works. This means that the problem is somewhere in the X configuration. >From a thread here https://bugs.freedesktop.org/show_bug.cgi?id=29273 I created an entry in xorg.conf Section "Device" Option "Backlight" "intel_backlight" Identifier "Card0" Driver "intel" BusID "PCI:0:2:0" EndSection I created this by using X -c and copying only relevant section to /etc/X11/xorg.conf The controls are working fine now. I *do not* have acpi_backlight=vendor . I just have acpi_osi=Linux , and I am not very sure if it is needed at all. ** Bug watch added: freedesktop.org Bugzilla #29273 https://bugs.freedesktop.org/show_bug.cgi?id=29273 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1007765 Title: brightness adjusting crashes system To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/fglrx-installer/+bug/1007765/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
