Missing brightness control in System Settings/Brightness and Lock

[Zafer Hamadeh]

There is something missing in the brightness and lock and i can not controll the brightnes.
zafer@zafer-G41MT-S2:~$ lsb_release -rd
Description: Ubuntu 12.04 LTS
Release: 12.04
Desktop version updaed from 11.10 to 12.04

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

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[rpr nospam (rpr-nospam)]

I can confirm this on a Ubuntu 12.04 64-bit after upgrade from 11.10. When the Brightness and Lock tool is started from command line it produces the following output:

$ gnome-control-center screen

(gnome-control-center:4353): screen-cc-panel-WARNING **: Error getting brightness: GDBus.Error:org.gtk.GDBus.UnmappedGError.Quark._gsd_5fpower_5fmanager_5ferror.Code0: gsd-backlight-helper failed:

Also, the /sys/class/backlight/ directory is empty.

Is there a way to fix this?

[Launchpad Janitor (janitor)]

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

[rpr nospam (rpr-nospam)]

I also tried to run gnome-control-center with sudo:

$ sudo gnome-control-center screen

(gnome-control-center:3122): screen-cc-panel-WARNING **: Error getting brightness: GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod: No such interface `org.gnome.SettingsDaemon.Power.Screen' on object at path /org/gnome/SettingsDaemon/Power

[Sebastien Bacher (seb128)]

Thank you for your bug report, could you add the .xsession-errors from a session having the issue?

[rpr nospam (rpr-nospam)]

Attaching ~/.xsession-errors

[Sebastien Bacher (seb128)]

Does it happen in a guest session as well?

what does "gsettings get org.gnome.desktop.background picture-uri" gives? does doing a gsettings reset on that key solve the issue?

[rpr nospam (rpr-nospam)]

Yes, it also happens in a guest session. I'm attaching the corresponding ~/.xsession-errors

I do not use a background picture on the desktop:
$ gsettings get org.gnome.desktop.background picture-uri
''

$ gsettings reset org.gnome.desktop.background picture-uri
$ gsettings get org.gnome.desktop.background picture-uri
'file:///usr/share/backgrounds/warty-final-ubuntu.png'

This gives back the default background picture but the Brightness and Lock tool still does not show the brightness slider.

[Sebastien Bacher (seb128)]

"** (gsd-backlight-helper:3003): WARNING **: failed to find any devices" is likely the issue, could be a kernel bug...

[Launchpad Janitor (janitor)]

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

[George T (lives9)]

Have the same problem with my msi ge 600 laptop. Driver issue likely because I can adjast brightness switching to another video card.

lshw -c video
  *-display
       VGA compatible controller
       Madison [Mobility Radeon HD 5000 Series]
       Hynix Semiconductor (Hyundai Electronics)
        ID: 0
       bus info: pci@0000:01:00.0
       version: 00
       64 bits
       33MHz
       pm pciexpress msi vga_controller bus_master cap_list rom
       driver=fglrx_pci latency=0
       IRQ:46 memory:e0000000-efffffff memory:f0020000-f003ffff ioport:d000(size=256) memory:f0000000-f001ffff

[S (skywinston-sk)]

This happened to me as well, and I'm on
14.04 Trusty Gnome

It happened to me because I deleted the default key ring which then brought other failures

Not sure if thats a bug or not, but it might be a good idea to have the "default key" default to nothing if it isn't specified