Public bug reported:
I am using an Acer V5-122P which uses the AMD Radeon 8250 graphics card.
I am unable to adjust the backlight brightness, except that on battery
if I try to toggle the brightness using the hotkeys up and down
repeatedly, I am able to adjust the backlight brightness to the lowest
setting. I am using Ubuntu 14.04 and fglrx, but the problem persists
when using the open source xorg-radeon/ati driver. I have been
experiencing this problem with all kernels and versions of Ubuntu since
12.04 with no changes as I've upgraded.
I have entries in /sys/class/backlight/acpi_video0/ for brightness,
max_brightness, actual_brightness, bl_power, type, device, subsystem,
power, and uevent.. Directly echoing values into brightness does not
make any changes to the screen brightness.
Happy to answer any other questions or try any workarounds.
Thanks,
Will
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
NonfreeKernelModules: fglrx
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: will 2915 F.... pulseaudio
/dev/snd/controlC0: will 2915 F.... pulseaudio
CurrentDesktop: Unity
Date: Wed May 21 23:49:10 2014
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=1cc8d8ae-deb7-4f44-a51b-1942c71e46fe
InstallationDate: Installed on 2013-07-20 (305 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
MachineType: Acer Aspire V5-122P
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic
root=UUID=b71ee9d9-bc02-4546-b41b-40305aed185c ro radeon.dpm=1 radeon.modeset=0
quiet splash 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 2014-05-02 (19 days ago)
dmi.bios.date: 04/16/2013
dmi.bios.vendor: Insyde Corp.
dmi.bios.version: V2.02.
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Aspire V5-122P
dmi.board.vendor: Acer
dmi.board.version: V2.02.
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: V2.02.
dmi.modalias:
dmi:bvnInsydeCorp.:bvrV2.02.:bd04/16/2013:svnAcer:pnAspireV5-122P:pvrV2.02.:rvnAcer:rnAspireV5-122P:rvrV2.02.:cvnAcer:ct10:cvrV2.02.:
dmi.product.name: Aspire V5-122P
dmi.product.version: V2.02.
dmi.sys.vendor: Acer
** Affects: linux (Ubuntu)
Importance: Undecided
Status: Confirmed
** Tags: amd64 apport-bug trusty
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1322004
Title:
Unable to adjust screen brightness
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1322004/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
