[Problem]:
Pushing the brightness "down" key causes the brightess to immediately go to a value of 0 yet the actual brightness has not change on the screen.
Pushing brightness "up" causes the brightness value to go up to around 5% and immediately sets the actual corresponding brightness level on the display.
At this point pressing the brightness "up" or "down" keys causes the brightness slider to jump between 0 and 5% but will not go any higher value setting.
You have to open gnome-control-center "brightness and lock" to reset the brightness to desired value.
This particular bug is present on a few recent lenovos models.
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.8.0-29-generic 3.8.0-29.42~precise1 [modified: boot/vmlinuz-3.8.0-29-generic]
ProcVersionSignature: Ubuntu 3.8.0-29.42~precise1-generic 3.8.13.5
Uname: Linux 3.8.0-29-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.4
Architecture: amd64
Date: Tue Sep 10 11:45:00 2013
InstallationMedia: Ubuntu 12.04.3 LTS "Precise Pangolin" - Release amd64 (20130820.1)
MarkForUpload: True
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: linux-lts-raring
UpgradeStatus: No upgrade log present (probably fresh install)
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version k3.8.0-29-generic.
ApportVersion: 2.0.1-0ubuntu17.4
Architecture: amd64
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC269VC Analog [ALC269VC Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: ubuntu 1563 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
Card hw:0 'PCH'/'HDA Intel PCH at 0xe2810000 irq 48'
Mixer name : 'Intel PantherPoint HDMI'
Components : 'HDA:10ec0269,17aa0001,00100203 HDA:80862806,80860101,00100000'
Controls : 36
Simple ctrls : 12
Card29.Amixer.info:
Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw unknown'
Mixer name : 'ThinkPad EC (unknown)'
Components : ''
Controls : 1
Simple ctrls : 1
Card29.Amixer.values:
Simple mixer control 'Console',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
DistroRelease: Ubuntu 12.04
HibernationDevice: RESUME=UUID=fbd820f1-0c28-488a-b1a5-90e425ff897e
InstallationMedia: Ubuntu 12.04.3 LTS "Precise Pangolin" - Release amd64 (20130820.1)
MachineType: LENOVO 20AX25C
MarkForUpload: True
Package: linux (not installed)
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-29-generic root=UUID=5cea22e2-4925-4f99-8469-1af7456106b3 ro quiet splash initcall_debug vt.handoff=7
ProcVersionSignature: Ubuntu 3.8.0-29.42~precise1-generic 3.8.13.5
RelatedPackageVersions:
linux-restricted-modules-3.8.0-29-generic N/A
linux-backports-modules-3.8.0-29-generic N/A
linux-firmware 1.79.6
Tags: precise running-unity
Uname: Linux 3.8.0-29-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
dmi.bios.date: 03/26/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: HFET25WW (1.02 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20AX25C
dmi.board.vendor: LENOVO
dmi.board.version: Win8 STD PRC DPK TPG
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrHFET25WW(1.02):bd03/26/2013:svnLENOVO:pn20AX25C:pvrThinkPadS3-S431:rvnLENOVO:rn20AX25C:rvrWin8STDPRCDPKTPG:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 20AX25C
dmi.product.version: ThinkPad S3-S431
dmi.sys.vendor: LENOVO
This is not an issue in the current Saucy kernel 3.11.0-6-generic.