When undocking the laptop panel brightness goes to minimum and cannot be increased

[Will Cooke]

My X220 sits on a docking station connected to (among other things) an external DisplayPort monitor. I have it set up so that I use both monitors.

When I undock the laptop, and so remove the external display, the laptop panel brightness goes to minimum and cannot be made brighter either via the function keys or the system settings slider.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-32-generic 3.13.0-32.57
ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4
Uname: Linux 3.13.0-32-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: will 2179 F.... pulseaudio
CurrentDesktop: Unity
Date: Fri Jul 25 10:15:40 2014
HibernationDevice: RESUME=UUID=48c1ab97-c081-4af0-a42d-2ffe656eed00
InstallationDate: Installed on 2013-12-24 (212 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MachineType: LENOVO 4287CTO
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-32-generic root=UUID=3238572a-b1a6-4e68-aade-1c58b750f578 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-32-generic N/A
 linux-backports-modules-3.13.0-32-generic N/A
 linux-firmware 1.127.5
SourcePackage: linux
UpgradeStatus: Upgraded to trusty on 2014-04-19 (96 days ago)
dmi.bios.date: 07/07/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 8DET50WW (1.20 )
dmi.board.asset.tag: Not Available
dmi.board.name: 4287CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr8DET50WW(1.20):bd07/07/2011:svnLENOVO:pn4287CTO:pvrThinkPadX220:rvnLENOVO:rn4287CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 4287CTO
dmi.product.version: ThinkPad X220
dmi.sys.vendor: LENOVO

[Brad Figg (brad-figg)]

This change was made by a bot.

[Will Cooke (willcooke)]

It seems that this only happens the first time I undock. If I re-dock the brightness goes back to as it was (e.g. full) and then subsequent un-docking keeps the brightness at the correct level.

[penalvch (penalvch)]

Will Cooke, thank you for reporting this and helping make Ubuntu better. As per http://download.lenovo.com/express/ddfm.html an update to your BIOS is available (1.39). If you update to this following https://help.ubuntu.com/community/BiosUpdate does it change anything? If it doesn't, could you please both specify what happened, and provide the output of the following terminal command:
sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date

Please note your current BIOS is already in the Bug Description, so posting this on the old BIOS would not be helpful. As well, you don't have to create a new bug report. As well, you don't have to create a new bug report.

For more on BIOS updates and linux, please see https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette .

Thank you for your understanding.

[Will Cooke (willcooke)]

I downloaded the latest BIOS ISO from the Lenovo website, but it seems to be broken. The ISO is empty. I'm trying to find an older version to see if that works. From the README with the BIOS update there is nothing which suggests anything do to with this bug has been fixed.

I'll keep trying though.

This didn't used to happen though, so my feeling is that its something introduced in 14.04. I can't prove it though.

[Roger Kind Kristiansen (rogerkk)]

This looks like a duplicate of https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1308674 ?

FWIW: I have upgraded my BIOS to the latest version (8DET69WW / 1.39) and I'm still seeing the same problem.