Backlight control doesn't work anymore on thinkpad

Bug #313231 reported by Sebastian Rühl
54
This bug affects 6 people
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Fix Released
Low
Andy Whitcroft
Nominated for Jaunty by A.Kromic

Bug Description

after a update from linux-image-2.6.27-10-generic to linux-image-2.6.27-11-generic the backlight control from my Thinkpad X61 Tablet doesn't work anymore.
It is quite impossible to change the backlight nor with the hotkeys or trough the sys-fs interface.
This is a real showstopper and should be fixed immediately as you can't read anything from the screen cause the screen is very dark. (Backlight is on but on the lowest level)

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Sebastian Rühl (sebastian-ruehl) wrote :
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Sebastian Rühl (sebastian-ruehl) wrote :
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Sebastian Rühl (sebastian-ruehl) wrote :
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Sebastian Rühl (sebastian-ruehl) wrote :
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Andy Whitcroft (apw) wrote :

@Sebastian -- I think this is very likely duplicate of bug #314119, which was fixed by (and now duplicate of) bug#311716. Could you test the kernels at the URL below:

    http://people.ubuntu.com/~apw/lp311716-intrepid/

The fixes for this will also very soon be in -proposed in version 2.6.27-11.23 so you could test it that way. Please see https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed.

Either way please try and test and report back here. Thank you in advance!

Changed in linux:
assignee: nobody → apw
importance: Undecided → Low
status: New → In Progress
Revision history for this message
Sebastian Rühl (sebastian-ruehl) wrote :

Currently I have this options in the /etc/modprobe.d/options

# Workaround
options thinkpad_acpi brightness_enable=1

Adjusting works... I could try to disable this and test again.
I will to this if I get some more free time (Currently a bit too busy)

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Pieter Hintjens (ph-imatix) wrote :

@Andy,

I'm hitting the same problem on an X61. Brightness stuck on maximum, since latest kernel upgrade.

The machine is running 2.6.27-11-generic.

I've tried to install the kernels at the URL you provided, but the packmage installer reports "Error: a later version is already installed", and stops. Changing thinkpad_acpi module options has no effect; I've tried reloading the module with all plausible options, no difference.

I know there are BIOS upgrades for the X61 and I'll try that if there's no other option. Do you have any other kernel URIs I can try?

Thanks!

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Andreas Schildbach (schildbach) wrote :

I've got the same problem on a Dell Latitude X1 (i915GMS).

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Pieter Hintjens (ph-imatix) wrote :

My workaround now is to reboot and change the brightness from grub(!)

$ dpkg -l | grep linux-image
ii linux-image-2.6.24-19-generic 2.6.24-19.41 Linux kernel image for version 2.6.24 on x86/x86_64
rc linux-image-2.6.24-21-generic 2.6.24-21.43 Linux kernel image for version 2.6.24 on x86/x86_64
ii linux-image-2.6.27-11-generic 2.6.27-11.27 Linux kernel image for version 2.6.27 on x86/x86_64
ii linux-image-2.6.27-7-generic 2.6.27-7.16 Linux kernel image for version 2.6.27 on x86/x86_64
ii linux-image-2.6.27-9-generic 2.6.27-9.19 Linux kernel image for version 2.6.27 on x86/x86_64
ii linux-image-generic 2.6.27.11.14 Generic Linux kernel image
$ uname -r
2.6.27-11-generic
$ dpkg --status linux-image-2.6.27-11-generic
Package: linux-image-2.6.27-11-generic
Status: install ok installed
Priority: optional
Section: base
Installed-Size: 92184
Maintainer: Ubuntu Kernel Team <email address hidden>
Architecture: i386
Source: linux
Version: 2.6.27-11.27
Provides: fuse-module, ivtv-modules, kvm-api-4, linux-image, linux-image-2.6, ndiswrapper-modules-1.9, redhat-cluster-modules
Depends: initramfs-tools (>= 0.36ubuntu6), coreutils | fileutils (>= 4.0), module-init-tools (>= 3.3-pre11-4ubuntu3)
Pre-Depends: dpkg (>= 1.10.24)
Recommends: lilo (>= 19.1) | grub
Suggests: fdutils, linux-doc-2.6.27 | linux-source-2.6.27
Conflicts: hotplug (<< 0.0.20040105-1)
Description: Linux kernel image for version 2.6.27 on x86/x86_64
 This package contains the Linux kernel image for version 2.6.27 on
 x86/x86_64.
 .
 Also includes the corresponding System.map file, the modules built by the
 packager, and scripts that try to ensure that the system is not left in an
 unbootable state after an update.
 .
 Supports Generic processors.
 .
 Geared toward desktop systems.
 .
 You likely do not want to install this package directly. Instead, install
 the linux-generic meta-package, which will ensure that upgrades work
 correctly, and that supporting packages are also installed.

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VictorGreen (publicpolicywonk) wrote :

Confirmed

X61, Intrepid 64 bit,
x@xcomp :~$ uname -r
                       2.6.27-11-generic

On screen display comes up and the slider moves but brightness is constant.

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temugen (temugen) wrote :

Any updates on this?

Bug confirmed:
X61s
2.6.27-11-generic
The function keys do not adjust the backlight brightness
same dmesg
brightness_enable=1 has no result
acpitool -l adjusts brightness just fine

executing:
xrandr --output LVDS --set BACKLIGHT_CONTROL native
makes everything function "properly"

I've looked into the acpi events and scripts, and I don't think the problem resides there.
I can provide more information and logs.

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A.Kromic (akromic) wrote :

I have the same problem on ThinkPad R61i. As of version 2.6.27-12 this hasn't been fixed. I propose the priority of this bug should be raised - as far as I am concerned it makes my laptop near unusable. Therefore I still boot to 2.6.27-10 and I don't intend to boot to any newer revision which doesn't let me control screen brightness.

On a side note, 2.6.27-11 has also introduced another annoyance for me which was deactivation of th WLAN adapter when controlling it and BT with Fn-F5 keys. Fortunately it has been fixed in -12. I wonder what they did to the kernel in -11?

If a log would help, please ask and I'll send...

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A.Kromic (akromic) wrote :

I forgot to say, I also use AMD64 version, and Gnome Brightness applet also fails to change brightness on -11 and -12

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Pieter Hintjens (ph-imatix) wrote :

@akromic: thanks for the tip of rebooting with an older kernel. I've reverted to 2.6.27.9 and the brightness controls work again.

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A.Kromic (akromic) wrote :

@P.H. You're welcome!

Just to add, with 2.6.27-13 still not working. This time at least it booted at full-bright, so I'll try the -13 for a while, but I guess I'll mark -10 as GRUB default again :(

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Michael Tänzer (neoatnhng) wrote :

I have the same problem on my Thinkpad R61, an update to the latest proposed kernel (2.6.27-13.29) didn't help.

The brightness stays at 100%

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A.Kromic (akromic) wrote :

Why is this marked as Low priority? Though it is limited to Lenovo/ThinkPad laptop users, it is a serious usability issue to us.

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Noel J. Bergman (noeljb) wrote :

FYI, I have a Thinkpad T61p (6457-7WU), and the brightness controls are working just fine with currently updated versions of 8.04, 8.10 and 9.04. To be sure, I have just rebooted on all of them to check.

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temugen (temugen) wrote :

Somewhere on a reboot after the session where I executed xrandr, my brightness controls began functioning as normal - Thinkpad X61s, other details available in my last comment.

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Michael Tänzer (neoatnhng) wrote :

I can confirm the xrandr solution described by temugen, but on my system it doesn't survive a reboot (I'm back on 2.6.27-11)

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A.Kromic (akromic) wrote :

Still doesn't work at kernel version *-14.
Xrandr solution works for a session.

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temugen (temugen) wrote :

I wish I could tell you guys what my fix was :-/ I realize how annoying and inconvenient this bug is.

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A.Kromic (akromic) wrote :

Considering what says on this page: https://wiki.ubuntu.com/Bugs/Importance

this bug could even be marked as High importance because it satisfies several of the listed criteria:

High: A bug which fulfills one of the following criteria:

    * Has a severe impact on a small portion of Ubuntu users (estimated) <---
    * Makes a default Ubuntu installation generally unusable for some users <---
          o For example, if the system fails to boot, or X fails to start, on a certain make and model of computer
    * A problem with an essential hardware component (disk controller, laptop built-in wireless, video card, keyboard, mouse) <---
    * Has a moderate impact on a large portion of Ubuntu users (estimated)

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Sebastian Rühl (sebastian-ruehl) wrote :

what is about my workaround: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/313231/comments/6
maybe this helps...

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Michael Tänzer (neoatnhng) wrote :

@Sebastian:
Sorry, didn't try your workaround before.

I can confirm Sebastian's workaround for my system (R61 - chipset Intel GM965 - graphics Intel X3100) it even solves the problem that there was a delay between hitting the backlight control keys and the actual update of the backlight brightness.

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David Ho (itsdho) wrote :

This bug affects me too, but I can confirm that Michael's workaround works for me.
I have the same system as Michael (R61, with Intel X3100 graphics).

Before applying Sebastian's workaround, nothing would change the backlight brightness: not the function keys (Fn+Home and Fn+End), not even gnome-power-manager. The backlight brightness did not reduce on battery power, either.

Hitting the function keys would update the on-screen brightness indicator (although there was a very long delay between keypress and update.) However, the actual brightness of my screen was unchanged.

This problem only occurred after upgrading to Intrepid for me.

After applying the workaround, everything works as it should. =)

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A.Kromic (akromic) wrote :

It works ok for me again with Jaunty.

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Pieter Hintjens (ph-imatix) wrote :

Have just upgraded to Ubuntu 9.04 and I can confirm that the problem has been fixed for Thinkpad X61.

Changed in linux (Ubuntu):
status: In Progress → Fix Released
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