Sometimes can't adjust screen brightness

[Mike Doherty]

Sometimes, the screen brightness controls work on my laptop, and sometimes they don't. I haven't noticed any pattern as to when it works or doesn't.

When it doesn't work, I press Fn+F6/F7 to adjust the screen brightness. The notification pop-up appears, showing the new brightness setting -- but the brightness doesn't actually change. Rebooting fixes the issue. There is nothing in syslog or dmesg.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-24-generic 3.13.0-24.47
ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: mike 4459 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue May 20 09:55:01 2014
HibernationDevice: RESUME=UUID=f989c947-43a9-46bf-9966-d1defa7837e3
InstallationDate: Installed on 2013-01-12 (492 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
MachineType: TOSHIBA TECRA R700
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-24-generic root=/dev/mapper/ubuntu-root ro quiet splash crashkernel=384M-:128M crashkernel=384M-:128M vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-24-generic N/A
 linux-backports-modules-3.13.0-24-generic N/A
 linux-firmware 1.127.2
SourcePackage: linux
UpgradeStatus: Upgraded to trusty on 2014-05-08 (11 days ago)
dmi.bios.date: 12/22/2011
dmi.bios.vendor: TOSHIBA
dmi.bios.version: Version 2.20
dmi.board.asset.tag: 0000000000
dmi.board.name: Portable PC
dmi.board.vendor: TOSHIBA
dmi.board.version: Version A0
dmi.chassis.asset.tag: 0000000000
dmi.chassis.type: 10
dmi.chassis.vendor: TOSHIBA
dmi.chassis.version: Version 1.0
dmi.modalias: dmi:bvnTOSHIBA:bvrVersion2.20:bd12/22/2011:svnTOSHIBA:pnTECRAR700:pvrPT318C-00F001:rvnTOSHIBA:rnPortablePC:rvrVersionA0:cvnTOSHIBA:ct10:cvrVersion1.0:
dmi.product.name: TECRA R700
dmi.product.version: PT318C-00F001
dmi.sys.vendor: TOSHIBA

[Brad Figg (brad-figg)]

This change was made by a bot.

[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 v3.15 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/v3.15-rc5-utopic/

[Launchpad Janitor (janitor)]

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