Public bug reported: Hello, i had and have and will this problem on every laptop and with every version of ubuntu and its derivatives.
I installed lubuntu 14.04 on IBM lenovo laptop with intel graphic card and my backlight could be changed with function keys but it goes either to maximum or minimum. it is similar to my bug previous bug report https://bugs.launchpad.net/ubuntu/+source/linux/+bug/990932 but this time i can change it before and after login but as i said either to max or min ... i tried couple of things to solve the problem via trial and error: - edited grub conf file and changed "acpi_backlight=legacy" line to ""acpi_backlight=vendor" - i created a file /usr/share/X11/xorg.conf.d/20-intel.conf here and edited it like this: Section "Device" Identifier "card0" Driver "intel" Option "Backlight" # "intel_backlight" BusID "PCI:0:2:0" EndSection (i tried both of "Backlight" and "intel_backlight" options) -and when i start the xubuntu power manager and try to set backlight (which is installed in lubuntu) i can see the backlight widget on the screen but it doesn't effect anything, still backlight goes to max or min, but the widget's animation cannot go further than one step, it stucks on the first step. - i tried to change the value of brightness file under the directory /sys/class/backlight/ideapad but sudo does not work here, it says permission denied, but when i read the value of actual_brightness file i can see 0 or 10 ( of course just these) First of all i don't think this is related to kernel, and i don't wanna try upstream kernel. I think it is related to xserver package and ubuntu acpi management and many configurations file in ubuntu that i don't know exactly how many are and where they are... Thanks in advance ** Affects: xserver-xorg-video-intel (Ubuntu) Importance: Undecided Status: New ** Tags: backlight -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/1370505 Title: lubuntu 14.04 backlight maximum or minimum on lenovo laptop To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1370505/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp