You have been subscribed to a public bug: The screen brightness does not reliably respond to adjustments anymore since 14.10 release. Previously in 14.04 it was adjustable via a slider in Ubuntu Control Center and via the keyboard buttons (so there is driver and keyboard support for this laptop). Now the keyboard buttons as well as the slider have no effect and the brightness defaults to 100% which is on this device about five times brighter than the comfortable level, and strains the battery.
However about 1 in 20 bootups/logins, the brightness is adjustable, but when I logout/login again in the user session, it might again become locked to 100%. I have the suspicion that it depends on the loading of desktop configs or the time I wait before typing my password to login. ProblemType: Bug DistroRelease: Ubuntu 14.10 Package: unity 7.3.1+14.10.20141016-0ubuntu1 ProcVersionSignature: Ubuntu 3.16.0-25.33-generic 3.16.7 Uname: Linux 3.16.0-25-generic x86_64 .tmp.unity.support.test.0: ApportVersion: 2.14.7-0ubuntu8 Architecture: amd64 CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CompositorRunning: compiz CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0' CompositorUnredirectFSW: true CurrentDesktop: Unity Date: Sat Dec 6 12:20:50 2014 DistUpgraded: 2014-11-04 18:35:56,188 DEBUG enabling apt cron job DistroCodename: utopic DistroVariant: ubuntu DkmsStatus: virtualbox, 4.3.18, 3.16.0-24-generic, x86_64: installed virtualbox, 4.3.18, 3.16.0-25-generic, x86_64: installed EcryptfsInUse: Yes GraphicsCard: Intel Corporation Haswell-ULT Integrated Graphics Controller [8086:0a16] (rev 09) (prog-if 00 [VGA controller]) Subsystem: Lenovo Device [17aa:3978] InstallationDate: Installed on 2014-02-02 (306 days ago) InstallationMedia: Ubuntu-GNOME 14.04 "Trusty Tahr" - Alpha amd64 (20140201) MachineType: LENOVO 20266 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-25-generic.efi.signed root=UUID=4bfb3686-b9f7-487d-81f6-eceb41097ad9 ro quiet splash acpi_backlight=vendor vt.handoff=7 SourcePackage: unity UpgradeStatus: Upgraded to utopic on 2014-11-04 (31 days ago) XorgConf: dmi.bios.date: 10/31/2013 dmi.bios.vendor: LENOVO dmi.bios.version: 76CN31WW dmi.board.asset.tag: No Asset Tag dmi.board.name: Yoga2 dmi.board.vendor: LENOVO dmi.board.version: 31900058STD dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Lenovo Yoga 2 Pro dmi.modalias: dmi:bvnLENOVO:bvr76CN31WW:bd10/31/2013:svnLENOVO:pn20266:pvrLenovoYoga2Pro:rvnLENOVO:rnYoga2:rvr31900058STD:cvnLENOVO:ct10:cvrLenovoYoga2Pro: dmi.product.name: 20266 dmi.product.version: Lenovo Yoga 2 Pro dmi.sys.vendor: LENOVO version.compiz: compiz 1:0.9.12+14.10.20140918-0ubuntu1 version.ia32-libs: ia32-libs N/A version.libdrm2: libdrm2 2.4.56-1 version.libgl1-mesa-dri: libgl1-mesa-dri 10.3.0-0ubuntu3 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 10.3.0-0ubuntu3 version.xserver-xorg-core: xserver-xorg-core 2:1.16.0-1ubuntu1 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.4.0-2ubuntu2 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.914-1~exp1ubuntu4.1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2 xserver.bootTime: Sat Dec 6 12:19:59 2014 xserver.configfile: /etc/X11/xorg.conf xserver.errors: xserver.logfile: /var/log/Xorg.0.log xserver.outputs: product id 16970 vendor SDC xserver.version: 2:1.16.0-1ubuntu1 ** Affects: linux (Ubuntu) Importance: Low Status: Incomplete ** Tags: amd64 apport-bug compiz-0.9 third-party-packages ubuntu utopic -- screen brightness cannot be changed anymore https://bugs.launchpad.net/bugs/1399900 You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp