Public bug reported: When I press Fn+Up/Down on my keyboard (the brightness adjust hotkey), the brightness settings the slider moves, however the actual brightness of my laptop display remains the same.
As per https://wiki.ubuntu.com/Kernel/Debugging/Backlight, I have attached the output of several commands as debugging information. Using the kernel parameter acpi_backlight=vendor, I can no longer adjust the brightness slider with my keyboard hotkey Fn+Up/Down Arrow, and when I go to System Settings -> Brightness & Lock, the brightness slider is no longer present. The kernel paramater video.use_bios_initial_backlight=0 appears to make no difference, as I can move the brightness slider and it still has no effect. The kernel paramater video.use_native_backlight=1 also has no noticeable effect. When booting with the latest mainline kernel (v3.15-rc5-utopic), the issue persists. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.13.0-24-generic 3.13.0-24.47 ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9 Uname: Linux 3.13.0-24-generic x86_64 ApportVersion: 2.14.1-0ubuntu3 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: travis 1559 F.... pulseaudio /dev/snd/controlC0: travis 1559 F.... pulseaudio CurrentDesktop: Unity Date: Fri May 16 17:55:54 2014 HibernationDevice: RESUME=UUID=85b9a9be-afa0-404e-8b11-c98f93fa4366 InstallationDate: Installed on 2014-05-14 (2 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) MachineType: LENOVO 20217 ProcEnviron: LANGUAGE=en_US PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 EFI VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic.efi.signed root=UUID=108a3bcd-f7e8-46e6-b5b8-1c1c0fb22903 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 1.127.2 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 09/18/2013 dmi.bios.vendor: LENOVO dmi.bios.version: 74CN44WW(V3.05) dmi.board.asset.tag: No Asset Tag dmi.board.name: VIQY0Y1 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 IdeaPad Y510P dmi.modalias: dmi:bvnLENOVO:bvr74CN44WW(V3.05):bd09/18/2013:svnLENOVO:pn20217:pvrLenovoIdeaPadY510P:rvnLENOVO:rnVIQY0Y1:rvr31900058STD:cvnLENOVO:ct10:cvrLenovoIdeaPadY510P: dmi.product.name: 20217 dmi.product.version: Lenovo IdeaPad Y510P dmi.sys.vendor: LENOVO ** Affects: linux (Ubuntu) Importance: Undecided Status: Confirmed ** Tags: amd64 apport-bug backlight brightness ideapad kernel-bug-exists-upstream lenovo trusty y510p -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1320412 Title: [Lenovo IdeaPad y510p] Brightness settings do not affect the actual display brightness To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1320412/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
