This might be related to bug 1324529. On my Lenovo T530, there is only thinkpad_screen in /sys/class/backlight. The fixes suggested here (the acpi_backlight=vendor and 80-backlight.conf) do not fix the issue for me and echoing numbers into /sys/class/backlight/thinkpad_screen/brightness does nothing.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1307064 Title: Ubuntu 14.04 Beta cannot adjust brightness on Lenovo Ideapad Z570 Status in “linux” package in Ubuntu: Incomplete Bug description: Fresh install of 14.04 on my laptop cannot adjust brightness. When fn+up arrow or fn+down arrow are used, the indicator in the upper right hand corner as if the brightness should change, but it does not. Also, if one tries to use the slider in the power applet, the brightness does not change. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.13.0-24-generic 3.13.0-24.46 ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9 Uname: Linux 3.13.0-24-generic x86_64 ApportVersion: 2.14.1-0ubuntu2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: will 2960 F.... pulseaudio CurrentDesktop: Unity Date: Sat Apr 12 21:36:57 2014 HibernationDevice: RESUME=UUID=dfa51f33-0f34-4383-8194-93656983323d InstallationDate: Installed on 2014-04-13 (0 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326) MachineType: LENOVO 10249RU ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic.efi.signed root=UUID=7420c61f-1836-4a44-84dc-71573190ff4c ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.13.0-24-generic N/A linux-backports-modules-3.13.0-24-generic N/A linux-firmware 1.127 SourcePackage: linux StagingDrivers: rts5139 UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 10/21/2011 dmi.bios.vendor: LENOVO dmi.bios.version: 45CN38WW dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: Emerald Lake dmi.board.vendor: LENOVO dmi.board.version: FAB1 dmi.chassis.asset.tag: Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: 0.1 dmi.modalias: dmi:bvnLENOVO:bvr45CN38WW:bd10/21/2011:svnLENOVO:pn10249RU:pvrIdeapadZ570:rvnLENOVO:rnEmeraldLake:rvrFAB1:cvnLENOVO:ct10:cvr0.1: dmi.product.name: 10249RU dmi.product.version: Ideapad Z570 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1307064/+subscriptions -- 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
