I'd like to perform a bisect to figure out what commit caused this regression. We need to identify the earliest kernel where the issue started happening as well as the latest kernel that did not have this issue.
Can you test the following kernels and report back? We are looking for the first kernel version that exhibits this bug: v3.12 final: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.12-trusty/ If v3.12 final does not exhibit the bug, we should move on to testing some of the v3.13 release candidates. v3.13-rc3: http://kernel.ubuntu.com/~kernel- ppa/mainline/v3.13-rc3-trusty/ If v3.13-rc3 does not exhibit the bug then test v3.13-rc6: v3.13-rc6: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.13-rc6-trusty/ If v3.13-rc3 does exhibit the bug then test v3.13-rc2: v3.13-rc2: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.13-rc2-trusty You don't have to test every kernel, just up until the kernel that first has this bug. Thanks in advance! ** Changed in: linux (Ubuntu) Status: Incomplete => Triaged ** Tags added: performing-bisect -- 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/1309584 Title: [HP EliteBook Folio 9470m Notebook PC] Backlight does not work on intel driver after upgrade from 13.10 -> 14.04, acpi_backlight=vendor solves Status in “linux” package in Ubuntu: Triaged Bug description: I am running on an HP EliteBook Folio 9470m which has an i915 video chipset. After upgrading to 14.04, the backlight and brightness controls do not work on the laptop screen. $ sudo intel_backlight current backlight value: 4% ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: xserver-xorg-video-intel 2:2.99.910-0ubuntu1 ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9 Uname: Linux 3.13.0-24-generic x86_64 .tmp.unity.support.test.0: ApportVersion: 2.14.1-0ubuntu3 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: Fri Apr 18 08:02:05 2014 DistUpgraded: 2014-04-18 01:03:05,027 DEBUG enabling apt cron job DistroCodename: trusty DistroVariant: ubuntu DkmsStatus: openvswitch, 2.0.1+git20140120: added ExtraDebuggingInterest: Yes, including running git bisection searches GraphicsCard: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller]) Subsystem: Hewlett-Packard Company Device [103c:18df] InstallationDate: Installed on 2013-01-14 (459 days ago) InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64+mac (20121017.3) MachineType: Hewlett-Packard HP EliteBook Folio 9470m ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-24-generic root=/dev/mapper/ubuntu-root ro quiet splash "acpi_osi=!Windows 2012" vt.handoff=7 SourcePackage: xserver-xorg-video-intel UpgradeStatus: Upgraded to trusty on 2014-04-18 (0 days ago) dmi.bios.date: 09/24/2012 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: 68IBD Ver. F.30 dmi.board.name: 18DF dmi.board.vendor: Hewlett-Packard dmi.board.version: KBC Version 62.13 dmi.chassis.asset.tag: CNU2439PZT dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.modalias: dmi:bvnHewlett-Packard:bvr68IBDVer.F.30:bd09/24/2012:svnHewlett-Packard:pnHPEliteBookFolio9470m:pvrA1029D1103:rvnHewlett-Packard:rn18DF:rvrKBCVersion62.13:cvnHewlett-Packard:ct10:cvr: dmi.product.name: HP EliteBook Folio 9470m dmi.product.version: A1029D1103 dmi.sys.vendor: Hewlett-Packard version.compiz: compiz 1:0.9.11+14.04.20140409-0ubuntu1 version.ia32-libs: ia32-libs N/A version.libdrm2: libdrm2 2.4.52-1 version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.0-4ubuntu5 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.0-4ubuntu5 version.xserver-xorg-core: xserver-xorg-core 2:1.15.1-0ubuntu2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2 xserver.bootTime: Fri Apr 18 01:04:29 2014 xserver.configfile: default xserver.errors: xserver.logfile: /var/log/Xorg.0.log xserver.outputs: product id 5239 vendor CMN xserver.version: 2:1.15.1-0ubuntu2 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1309584/+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
