The issue does not occur anymore. It has been fixed, but not completely satisfactory, by a workaround in the kernel to use an older backlight control method than one comparable to Windows 8 which provides a more finegraned control. All in all backlight control support is back to the level of quantal in raring and saucy: functional.
I just tried to install the 2.57 update, but the updater told me that I already have the latest version. $ sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date G4ET97WW (2.57 ) 10/17/2013 -- 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/1173984 Title: 8086:0166 [Lenovo ThinkPad T530] Backlight control via fn-keys is stuck in certain ranges Status in “linux” package in Ubuntu: Incomplete Bug description: I just upgraded my quantal installation on my Lenovo T530 to raring and found the backlight control via fn-keys not functioning properly as it did in quantal. The backlight is initially set to 100% and can only be reduced to 95%. Setting the value to lower levels, brightness can the be controlled via fn-keys between 95% and 80%, 80% and 20%. The last range is from 20% to 0%. When booting raring with the quantal kernel, brightness can be controlled without issues. The system is setup with UEFI and only Intel graphics (no hybrid). Clean MBR installation of raring to an external drive shows the same issue. --- ApportVersion: 2.9.2-0ubuntu8 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: livewire 2491 F.... pulseaudio CRDA: country DE: (2400 - 2483 @ 40), (N/A, 20) (5150 - 5250 @ 40), (N/A, 20), NO-OUTDOOR (5250 - 5350 @ 40), (N/A, 20), NO-OUTDOOR, DFS (5470 - 5725 @ 40), (N/A, 26), DFS DistroRelease: Ubuntu 13.04 HibernationDevice: RESUME=UUID=75748ef4-e058-4ab6-be00-a6dd36ebcad0 InstallationDate: Installed on 2012-10-20 (190 days ago) InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5) MachineType: LENOVO 2392CTO MarkForUpload: True Package: linux (not installed) ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-19-generic root=UUID=54762617-6f49-4a10-9c05-e6f9af033bd3 ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8 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 Tags: raring Uname: Linux 3.8.0-19-generic x86_64 UpgradeStatus: Upgraded to raring on 2013-04-28 (0 days ago) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo dmi.bios.date: 12/20/2012 dmi.bios.vendor: LENOVO dmi.bios.version: G4ET90WW (2.50 ) dmi.board.asset.tag: Not Available dmi.board.name: 2392CTO dmi.board.vendor: LENOVO dmi.board.version: Not Defined dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvrG4ET90WW(2.50):bd12/20/2012:svnLENOVO:pn2392CTO:pvrThinkPadT530:rvnLENOVO:rn2392CTO:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 2392CTO dmi.product.version: ThinkPad T530 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1173984/+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
