As (probably) a large number of user on linux right now, I'm using the following workaround to handle this issue:
'echo "4590" > /sys/class/backlight/intel_backlight/brightness' as root another option might be to use the following xrandr command: xrandr --output [yourscreendevice] -- 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/1225811 Title: 1002:6601 [Dell Inspiron 15R 5521] Can't toggle backlight brightness Status in “linux” package in Ubuntu: Confirmed Bug description: Since raring at least, it is not possible to change backlight brightness. WORKAROUND: Add acpi_backlight=vendor into grub boot option. ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: linux-image-generic 3.11.0.7.8 ProcVersionSignature: Ubuntu 3.11.0-5.11-generic 3.11.0 Uname: Linux 3.11.0-5-generic x86_64 ApportVersion: 2.12.1-0ubuntu4 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: nicolas 2839 F.... pulseaudio Date: Mon Sep 16 02:05:10 2013 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=173db09c-bffc-4da9-ab42-7ca73f84e71f InstallationDate: Installed on 2013-04-08 (160 days ago) InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5) MachineType: Dell Inc. Inspiron 5521 MarkForUpload: True ProcFB: 0 inteldrmfb 1 radeondrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-5-generic root=UUID=09af3e13-8004-48fa-b0fe-116acbf8d3d7 ro crashkernel=384M-2G:64M,2G-:128M quiet splash acpi_backlight=vendor vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.11.0-5-generic N/A linux-backports-modules-3.11.0-5-generic N/A linux-firmware 1.114 SourcePackage: linux StagingDrivers: rts5139 UpgradeStatus: Upgraded to saucy on 2013-06-24 (83 days ago) dmi.bios.date: 06/25/2013 dmi.bios.vendor: Dell Inc. dmi.bios.version: A09 dmi.board.name: 0HK2KG dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: A09 dmi.modalias: dmi:bvnDellInc.:bvrA09:bd06/25/2013:svnDellInc.:pnInspiron5521:pvrA09:rvnDellInc.:rn0HK2KG:rvrA00:cvnDellInc.:ct8:cvrA09: dmi.product.name: Inspiron 5521 dmi.product.version: A09 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1225811/+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
