8086:0166 [Lenovo ThinkPad X1 Carbon] Brightness stepping is incorrect (double what it should be)

[Anmar Oueja]

Problem: When I press the laptop screen brighteness, each step yield an event that is displayed on the OSD but the screen brightness doesn't change until the third press. Same happens for decreasing or increasing the brightness.

Exepcted behaviour: Each press of the brightness button on the laptop, yield a visible change in the brightness of the LCD scree.

Workaround: This seems documented and works perfectly. The work around is to type this in terminal:

sudo sh -c 'echo -n 0 > /sys/module/video/parameters/brightness_switch_enabled'

More details are here: http://askubuntu.com/questions/173921/why-does-my-thinkpad-brightness-control-skip-steps

I think this should be fixed in 13.10.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: linux-image-3.11.0-4-generic 3.11.0-4.9
ProcVersionSignature: Ubuntu 3.11.0-4.9-generic 3.11.0-rc7
Uname: Linux 3.11.0-4-generic x86_64
ApportVersion: 2.12.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: anmar 1798 F.... pulseaudio
Date: Fri Sep 6 11:23:20 2013
HibernationDevice: RESUME=UUID=2e39ee55-2a87-4298-a2d0-1c8ef5de5a96
InstallationDate: Installed on 2013-08-09 (27 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130809)
MachineType: LENOVO 3443CTO
MarkForUpload: True
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-4-generic.efi.signed root=UUID=1784df7c-8b5f-4550-84f2-13e73c2915fe ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.11.0-4-generic N/A
 linux-backports-modules-3.11.0-4-generic N/A
 linux-firmware 1.113
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/29/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: G6ET96WW (2.56 )
dmi.board.asset.tag: Not Available
dmi.board.name: 3443CTO
dmi.board.vendor: LENOVO
dmi.board.version: Win8 STD 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:bvrG6ET96WW(2.56):bd04/29/2013:svnLENOVO:pn3443CTO:pvrThinkPadX1Carbon:rvnLENOVO:rn3443CTO:rvrWin8STDDPKTPG:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 3443CTO
dmi.product.version: ThinkPad X1 Carbon
dmi.sys.vendor: LENOVO

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a kernel version where you were not having this particular problem? This will help determine if the problem you are seeing is the result of the introduction of a regression, and when this regression was introduced. If this is a regression, we can perform a kernel bisect to identify the commit that introduced the problem.

[Anmar Oueja (anmar)]

I will check 3.10 and earlier 3.11 RCs to see if I can narrow it down.

On 6 September 2013 11:47, Joseph Salisbury
<email address hidden> wrote:
> Did this issue start happening after an update/upgrade? Was there a
> kernel version where you were not having this particular problem? This
> will help determine if the problem you are seeing is the result of the
> introduction of a regression, and when this regression was introduced.
> If this is a regression, we can perform a kernel bisect to identify the
> commit that introduced the problem.
>
> ** Changed in: linux (Ubuntu)
> Importance: Undecided => Medium
>
> ** Changed in: linux (Ubuntu)
> Status: Confirmed => Incomplete
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1221795
>
> Title:
> brightness stepping is incorrect (double what it should be)
>
> Status in “linux” package in Ubuntu:
> Incomplete
>
> Bug description:
> Problem: When I press the laptop screen brighteness, each step yield
> an event that is displayed on the OSD but the screen brightness
> doesn't change until the third press. Same happens for decreasing or
> increasing the brightness.
>
> Exepcted behaviour: Each press of the brightness button on the laptop,
> yield a visible change in the brightness of the LCD scree.
>
> Workaround: This seems documented and works perfectly. The work around
> is to type this in terminal:
>
> sudo sh -c 'echo -n 0 >
> /sys/module/video/parameters/brightness_switch_enabled'
>
> More details are here: http://askubuntu.com/questions/173921/why-does-
> my-thinkpad-brightness-control-skip-steps
>
> I think this should be fixed in 13.10.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 13.10
> Package: linux-image-3.11.0-4-generic 3.11.0-4.9
> ProcVersionSignature: Ubuntu 3.11.0-4.9-generic 3.11.0-rc7
> Uname: Linux 3.11.0-4-generic x86_64
> ApportVersion: 2.12.1-0ubuntu3
> Architecture: amd64
> AudioDevicesInUse:
> USER PID ACCESS COMMAND
> /dev/snd/controlC0: anmar 1798 F.... pulseaudio
> Date: Fri Sep 6 11:23:20 2013
> HibernationDevice: RESUME=UUID=2e39ee55-2a87-4298-a2d0-1c8ef5de5a96
> InstallationDate: Installed on 2013-08-09 (27 days ago)
> InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130809)
> MachineType: LENOVO 3443CTO
> MarkForUpload: True
> ProcFB: 0 inteldrmfb
> ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-4-generic.efi.signed root=UUID=1784df7c-8b5f-4550-84f2-13e73c2915fe ro quiet splash vt.handoff=7
> RelatedPackageVersions:
> linux-restricted-modules-3.11.0-4-generic N/A
> linux-backports-modules-3.11.0-4-generic N/A
> linux-firmware 1.113
> SourcePackage: linux
> UpgradeStatus: No upgrade log present (probably fresh install)
> dmi.bios.date: 04/29/2013
> dmi.bios.vendor: LENOVO
> dmi.bios.version: G6ET96WW (2.56 )
> dmi.board.asset.tag: Not Available
> dmi.board.name: 3443CTO
> dmi.board.vendor: LENOVO
> dmi.board.version: Win8 STD DPK TPG
> dmi.chassis.asset.tag: No Asset Information
> dmi.chassis.type: 10
> dmi...

[Anmar Oueja (anmar)]

BTW, this command line option (acpi_backlight=vendor) fixes the
problem so I am now not sure if this is a bug or not.

On 6 September 2013 13:00, Anmar Oueja <email address hidden> wrote:
> I will check 3.10 and earlier 3.11 RCs to see if I can narrow it down.
>
> On 6 September 2013 11:47, Joseph Salisbury
> <email address hidden> wrote:
>> Did this issue start happening after an update/upgrade? Was there a
>> kernel version where you were not having this particular problem? This
>> will help determine if the problem you are seeing is the result of the
>> introduction of a regression, and when this regression was introduced.
>> If this is a regression, we can perform a kernel bisect to identify the
>> commit that introduced the problem.
>>
>> ** Changed in: linux (Ubuntu)
>> Importance: Undecided => Medium
>>
>> ** Changed in: linux (Ubuntu)
>> Status: Confirmed => Incomplete
>>
>> --
>> You received this bug notification because you are subscribed to the bug
>> report.
>> https://bugs.launchpad.net/bugs/1221795
>>
>> Title:
>> brightness stepping is incorrect (double what it should be)
>>
>> Status in “linux” package in Ubuntu:
>> Incomplete
>>
>> Bug description:
>> Problem: When I press the laptop screen brighteness, each step yield
>> an event that is displayed on the OSD but the screen brightness
>> doesn't change until the third press. Same happens for decreasing or
>> increasing the brightness.
>>
>> Exepcted behaviour: Each press of the brightness button on the laptop,
>> yield a visible change in the brightness of the LCD scree.
>>
>> Workaround: This seems documented and works perfectly. The work around
>> is to type this in terminal:
>>
>> sudo sh -c 'echo -n 0 >
>> /sys/module/video/parameters/brightness_switch_enabled'
>>
>> More details are here: http://askubuntu.com/questions/173921/why-does-
>> my-thinkpad-brightness-control-skip-steps
>>
>> I think this should be fixed in 13.10.
>>
>> ProblemType: Bug
>> DistroRelease: Ubuntu 13.10
>> Package: linux-image-3.11.0-4-generic 3.11.0-4.9
>> ProcVersionSignature: Ubuntu 3.11.0-4.9-generic 3.11.0-rc7
>> Uname: Linux 3.11.0-4-generic x86_64
>> ApportVersion: 2.12.1-0ubuntu3
>> Architecture: amd64
>> AudioDevicesInUse:
>> USER PID ACCESS COMMAND
>> /dev/snd/controlC0: anmar 1798 F.... pulseaudio
>> Date: Fri Sep 6 11:23:20 2013
>> HibernationDevice: RESUME=UUID=2e39ee55-2a87-4298-a2d0-1c8ef5de5a96
>> InstallationDate: Installed on 2013-08-09 (27 days ago)
>> InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130809)
>> MachineType: LENOVO 3443CTO
>> MarkForUpload: True
>> ProcFB: 0 inteldrmfb
>> ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-4-generic.efi.signed root=UUID=1784df7c-8b5f-4550-84f2-13e73c2915fe ro quiet splash vt.handoff=7
>> RelatedPackageVersions:
>> linux-restricted-modules-3.11.0-4-generic N/A
>> linux-backports-modules-3.11.0-4-generic N/A
>> linux-firmware 1.113
>> SourcePackage: linux
>> UpgradeStatus: No upgrade log present (probably fresh install)
>> dmi.bios.date: 04/29/2013
>> dmi.bios.ven...

[00x (00xads-deactivatedaccount-deactivatedaccount)]

For my Thinkpad T430s, I can confirm that adding acpi_backlight=vendor as a grub boot option fixes the problem. I only have the Intel GPU enabled.

However, applying this boot options result in the OSD not correctly showing the current brightness state (s. attachment); it has always the same state.

[00x (00xads-deactivatedaccount-deactivatedaccount)]

In finally managed to resolve the issue for my T430s. I had to add the following boot options to /etc/default/grub:

acpi_osi='!Windows 2012'
- This makes the OSD work properly with 8 brightness steps

video.brightness_switch_enabled=0
- This allows you to have 15 brightness steps (working OSD also included)

The following comments seem to be related:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1098216/comments/51
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1098216/comments/54

Maybe it's still a regression?

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

[penalvch (penalvch)]

Anmar Oueja, as per http://download.lenovo.com/express/ddfm.html an update is available for your BIOS (2.59). 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 just 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.

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

Thank you for your understanding.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]