Christopher M. Penalver, thanks for your clear instructions. I tested with linux-image-3.12.0-031200rc6-generic, and this problem persists. I also found that when booting the machine, I can adjust the brightness when GRUB2 is loaded, and then when I boot into Ubuntu, I'm stuck at whatever brightness level I had in GRUB2.
Good hunting, and thanks! I'll be happy to offer any more information you might need. ** Tags removed: needs-upstream-testing ** Tags added: kernel-bug-exists-upstream kernel-bug-exists-upstream-3.12.0-031200rc6 ** Changed in: linux (Ubuntu) Status: Incomplete => Confirmed -- 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/1178727 Title: 8086:0046 Screen brightness can not be adjusted in Raring with Intel Ironlake graphics Status in “linux” package in Ubuntu: Confirmed Bug description: What looks like a regression from this bug: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/573984 This issue had been resolved, and I had no problem with 12.04 or 12.10, but upon upgrading to 13.04, once again, I cannot adjust the screen brightness. It is stuck at 100%. ProblemType: Bug DistroRelease: Ubuntu 13.04 Package: linux-image-3.8.0-19-generic 3.8.0-19.30 ProcVersionSignature: Ubuntu 3.8.0-19.30-generic 3.8.8 Uname: Linux 3.8.0-19-generic x86_64 ApportVersion: 2.9.2-0ubuntu8 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: ethan 2358 F.... pulseaudio CheckboxSubmission: 4463f48e66443bc710cec4d3024fcac7 CheckboxSystem: 090f50ffa15f2babaae2e4e2bf775960 Date: Fri May 10 15:08:12 2013 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=c1607e74-253f-4660-bdb7-45f46947f909 Lsusb: Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 003: ID 064e:a103 Suyin Corp. Acer/HP Integrated Webcam [CN0314] MachineType: Gateway NV79 MarkForUpload: True ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-19-generic root=UUID=da8a8682-2f9b-4878-8b46-6d23657e2137 ro quiet splash acpi_backlight=vendor vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.8.0-19-generic N/A linux-backports-modules-3.8.0-19-generic N/A linux-firmware 1.106 SourcePackage: linux UpgradeStatus: Upgraded to raring on 2013-04-26 (14 days ago) dmi.bios.date: 04/25/2011 dmi.bios.vendor: Gateway dmi.bios.version: V1.08 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: NV79 dmi.board.vendor: Gateway dmi.board.version: V1.08 dmi.chassis.type: 10 dmi.chassis.vendor: Gateway dmi.chassis.version: V1.08 dmi.modalias: dmi:bvnGateway:bvrV1.08:bd04/25/2011:svnGateway:pnNV79:pvrV1.08:rvnGateway:rnNV79:rvrV1.08:cvnGateway:ct10:cvrV1.08: dmi.product.name: NV79 dmi.product.version: V1.08 dmi.sys.vendor: Gateway To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1178727/+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