changing brightness freezes computer

[Will Otte]

on startup, changing the brightness freezes the computer completely. After I wait around five minutes, I am able to change the brightness without causing it to freeze but until then, if I change it the computer freezes. I am not sure what package handles this.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gnome-settings-daemon 3.4.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic x86_64
ApportVersion: 2.0.1-0ubuntu5
Architecture: amd64
Date: Tue Apr 24 00:47:59 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120328)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-settings-daemon
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[James Bradwell (secretchief23)]

I can confirm this bug also occurs for me. I have a Dell Inspiron N5010 running 12.04 64-bit. It occurs also when when adjusting the brightness well after the computer has started up, although it seems the most consistent way of reproducing the bug is to try to adjust the brightness in the first minute or so after logging in. Also, I have the laptop set up not to suspend when I close the lid. Closing and opening the lid only causes the screen to turn off and on, which can also trigger a complete system freeze. When the freeze occurs, it IS complete: CTRL+ALT+SysReq doesn't work, nor can I switch to a command line view with CTRL+ALT+F1.

[James Bradwell (secretchief23)]

I should add that it is not just the brightness keys that trigger freezes. Adjusting the brightness graphically with the slider in the power settings also causes freezes to occur.

[Y.Sun (ysun)]

This bug also happens to me. I'm using Ubuntu 12.04 32-bit on HP mini 5101. The OS is used to freeze at random times almost everyday, so I followed suggestions in another bug report and manually updated the kernel to 3.4.0. Now it freezes when I adjust the brightness setting with the keyboard shortcut, regardless of how much time elapsed after booting, but if and only if I pressed the key more than one time or hold it down. Adjusting the brightless by just a bit does not freeze the system.

[Savio (abhijeet)]

yup. I'm using Ubuntu 12.04 amd64 this bug also accures to me. Sometimes it makes system to beep constantly.

[Manasvi Gupta (fatbabyin)]

Hello,

I am also affected by this issue.

However, It seems this issue has been identified as Kernel bug - https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1007765?comments=all

Thanks,
Manasvi Gupta

[Dave Gilbert (ubuntu-treblig)]

As per comment #7 this looks like a kernel issue so flipping to Linux.
High: System crash on ~critical hardware function

Note I'm not duping it to bug 1007765 since it's kernel, but it might be appropriate to do so; leave that to the kernel guys.

[Savio (abhijeet)]

I have Dell inspiron with Intel core I3 and Intel HD graphics with ubuntu. 13.04 .
I tried setting acpi_backlight=vendor but no help
but setting acpi = off works but no touchpad support

setting brightness manually in /sys/class/backlight/dell_ brightness/ current* to 1 works and also changing this setting multiple times works great

please help.

[Savio (abhijeet)]

Enabling nmi_watchdog solved this temp.
add /etc/rc.local
echo 0 >/proc/sys/kernel/nmi_watchdog

From comment #89 of bug 1007765 it seems that fix will be in 3.10 ..hope so.

Cheers.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.10 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.10-rc7-saucy/

[Launchpad Janitor (janitor)]

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

[Lucas Pottersky (lucaspottersky)]

Also happens to me.

3.2.0-51-generic #77-Ubuntu SMP Wed Jul 24 20:18:19 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux