Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?
Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.0 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'. If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-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/v4.0-rc3-vivid/ ** Changed in: linux (Ubuntu) Importance: Undecided => Medium -- 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/1430883 Title: continuously receive the message [drm:radeon_acpi_init] "ERROR" Cannot find a backlight controller Status in linux package in Ubuntu: Confirmed Bug description: [ 15.021664] rt3290sta: module verification failed: signature and/or required key missing - tainting kernel [ 16.182412] EXT4-fs (sda2): re-mounted. Opts: errors=remount-ro [ 24.058014] [drm:radeon_acpi_init] *ERROR* Cannot find a backlight controller [ 29.933827] init: failsafe main process (718) killed by TERM signal [ 32.111669] /var/lib/dkms/rt3290sta/2.6.0.0/build/src/os/linux/../../common/cmm_asic.c:2608 assert KeyIdx < 4failed [ 32.111678] /var/lib/dkms/rt3290sta/2.6.0.0/build/src/os/linux/../../common/cmm_asic.c:2608 assert KeyIdx < 4failed ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.13.0-46-generic 3.13.0-46.77 ProcVersionSignature: Ubuntu 3.13.0-46.77-generic 3.13.11-ckt15 Uname: Linux 3.13.0-46-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.7 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: eugene 2496 F.... pulseaudio /dev/snd/controlC0: eugene 2496 F.... pulseaudio CurrentDesktop: Unity Date: Wed Mar 11 19:02:59 2015 HibernationDevice: RESUME=UUID=b90f8319-66ea-4e2b-8b49-1434ed1e6f6d InstallationDate: Installed on 2015-03-05 (6 days ago) InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2) MachineType: Hewlett-Packard HP Pavilion 15 Notebook PC ProcFB: 0 radeondrmfb 1 radeondrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-46-generic root=UUID=e71f0d22-9d1d-4165-a8f5-bd2ac86c28b7 ro quiet splash acpi_backlight=vendor vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.13.0-46-generic N/A linux-backports-modules-3.13.0-46-generic N/A linux-firmware 1.127.11 RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 06/03/2014 dmi.bios.vendor: Insyde dmi.bios.version: F.15 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: 216C dmi.board.vendor: Hewlett-Packard dmi.board.version: 30.25 dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnInsyde:bvrF.15:bd06/03/2014:svnHewlett-Packard:pnHPPavilion15NotebookPC:pvr0887100000005E00000600000:rvnHewlett-Packard:rn216C:rvr30.25:cvnHewlett-Packard:ct10:cvrChassisVersion: dmi.product.name: HP Pavilion 15 Notebook PC dmi.product.version: 0887100000005E00000600000 dmi.sys.vendor: Hewlett-Packard To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1430883/+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
