@brad-figg: I did the tests you asked me. I now ran dist-upgrade and booted with the Acer laptop that suffers from this issue. It turned out the old workaround in comment #4 stopped working in the new kernel 3.2.0-18, that is in /etc/default/grub line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
I tried replacing it with GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=" and GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux" The second one was not good, as the Fn+Arrow right increased the backlight and Arrow left vice versa, but on this keyboard the buttons should go the other way around. However the former option responded to the buttons the right way. So if you are running a similar Acer laptop, this my recommended solution to get the Fn-buttons working is adding the line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=" to your /etc/default/grub and then run "sudo update-grub" This is however only 50 % of the solution. When the computer starts you probably want to see the screen by default without pressing Fn+Arrow left first. Therefore add to you /etc/rc.local file the line echo "1" > /sys/class/backlight/intel_backlight/brightness (put it just above the exit 0 line) The workaround in Comment #33 for bug #826386 suggets adding to rc.local the line "sudo setpci -s 00:02.0 F4.B=0", but I think my version is more verbose and robust to errors. Somebody with the skills should write a patch that detects this laptop make and inserts these two lines in grub and rc.local that fixes the issue. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/910536 Title: Screen too dark, no backlight, unusable X To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/910536/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
