Public bug reported: Fresh install of a Vivid Vervet Ubuntu GNOME daily iso.
Adding debugging information from https://wiki.ubuntu.com/Kernel/Debugging/Backlight I found that echo 8 > /sys/class/backlight/intel_backlight/brightness worked to lower my screen brightness, without playing with kernel parameters. Booting with the kernel parameter: acpi_backlight=vendor did not enable the UI widget or hotkeys, although echo 8 > /sys/class/backlight/intel_backlight/brightness continued to work. Booting with the kernel parameter: video.use_bios_initial_backlight=0 did not allow for hotkey or widget changes of brightness. Booting with the kernel parameter: video.use_native_backlight=1 Creating /usr/share/X11/xorg.conf.d/80-backlight.conf with the contents: Section "Device" Identifier "Intel Graphics" Driver "intel" Option "AccelMethod" "sna" Option "Backlight" "intel_backlight" # use your backlight that works here BusID "PCI:0:2:0" EndSection and rebooting does resolve the issue. ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: linux-image-3.16.0-24-generic 3.16.0-24.32 [modified: boot/vmlinuz-3.16.0-24-generic] ProcVersionSignature: Ubuntu 3.16.0-24.32-generic 3.16.4 Uname: Linux 3.16.0-24-generic x86_64 ApportVersion: 2.14.7-0ubuntu9 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: asif 2318 F.... pulseaudio CurrentDesktop: GNOME Date: Sun Nov 2 15:48:05 2014 HibernationDevice: RESUME=UUID=53025272-1910-418a-9f4a-b6ac00a768f1 InstallationDate: Installed on 2014-11-01 (1 days ago) InstallationMedia: Ubuntu-GNOME 15.04 "Vivid Vervet" - Alpha amd64 (20141031) MachineType: LENOVO 1066A9U ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.16.0-24-generic root=/dev/mapper/ubuntu--gnome--vg-root ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.16.0-24-generic N/A linux-backports-modules-3.16.0-24-generic N/A linux-firmware 1.138 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/11/2011 dmi.bios.vendor: LENOVO dmi.bios.version: 44CN36WW 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:bvr44CN36WW:bd07/11/2011:svnLENOVO:pn1066A9U:pvrLenovoV570:rvnLENOVO:rnEmeraldLake:rvrFAB1:cvnLENOVO:ct10:cvr0.1: dmi.product.name: 1066A9U dmi.product.version: Lenovo V570 dmi.sys.vendor: LENOVO ** Affects: linux (Ubuntu) Importance: Undecided Status: Confirmed ** Tags: amd64 apport-bug vivid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1388636 Title: Lenovo v570: Brightness not changing via UI widget in GNOME shell or hotkeys To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1388636/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
