Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.2 kernel[0].
If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'. If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'. Once testing of the upstream kernel is complete, please mark this bug as "Confirmed". Thanks in advance. [0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.2-rc7-unstable/ ** Changed in: linux (Ubuntu) Importance: Undecided => Medium ** Changed in: linux (Ubuntu) Status: Confirmed => Incomplete -- 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/1486896 Title: On Lenovo Thinkpad Edge E330, the screen backlight flickers badly. Status in linux package in Ubuntu: Incomplete Bug description: Behavior is the same on Ubuntu 14.04 -- 15.04. Steps were taken according to this: https://wiki.ubuntu.com/Kernel/Debugging/Backlight With acpi_backlight=vendor, the flicker stops, and the brightness control doesn't work. However, echo 8 > /sys/class/backlight/intel_backlight/brightness dims the screen. thinkpad-acpi.brightness_enable = 1 does nothing. Workaround: If no changes are made to boot options, and echo 4437 > /sys/class/backlight/intel_backlight/brightness is done, the flicker stops and the GUI control / acpi_video0 works, but causes flicker again. Attaching the necessary files. ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: linux-image-3.19.0-26-generic 3.19.0-26.28 ProcVersionSignature: Ubuntu 3.19.0-26.28-generic 3.19.8-ckt4 Uname: Linux 3.19.0-26-generic x86_64 ApportVersion: 2.17.2-0ubuntu1.3 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: mark 1391 F.... pulseaudio CurrentDesktop: Unity Date: Thu Aug 20 11:21:39 2015 HibernationDevice: RESUME=UUID=7a9e1f17-c57b-4e6f-bb0c-0b090b5d1405 InstallationDate: Installed on 2014-08-22 (363 days ago) InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2) MachineType: LENOVO 3354DGG ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.19.0-26-generic root=UUID=b566feb2-5a5c-4573-8782-b78d130dbc45 ro quiet splash acpi_backlight=vendor vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.19.0-26-generic N/A linux-backports-modules-3.19.0-26-generic N/A linux-firmware 1.143.3 SourcePackage: linux UpgradeStatus: Upgraded to vivid on 2015-08-20 (0 days ago) dmi.bios.date: 02/25/2013 dmi.bios.vendor: LENOVO dmi.bios.version: H3ET72WW(1.09) dmi.board.asset.tag: Not Available dmi.board.name: 3354DGG dmi.board.vendor: LENOVO dmi.board.version: 0B98409 Std dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvrH3ET72WW(1.09):bd02/25/2013:svnLENOVO:pn3354DGG:pvrThinkPadEdgeE330:rvnLENOVO:rn3354DGG:rvr0B98409Std:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 3354DGG dmi.product.version: ThinkPad Edge E330 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1486896/+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
