Here's a thread in the linux-thinkpad mailing list about this issue (it affects
XFCE as well as GNOME):
http://mailman.linux-thinkpad.org/pipermail/linux-thinkpad/2012-February/050576.html
The thinkpad-acpi kernel module maintainer says:
> This typically means broken crap that reacts to brightness *change* events as
> if they were keypresses.
Upstream bugs that seem related to this:
- ThinkPad X60s and X300, improper brightness adjustment using function keys
Fn+{Home,End}, twice long step
https://bugzilla.gnome.org/show_bug.cgi?id=579224
- Need a setting to tell g-p-m that brightness changes are handled in hardware
when using xrandr
https://bugzilla.gnome.org/show_bug.cgi?id=601410
** Bug watch added: GNOME Bug Tracker #579224
https://bugzilla.gnome.org/show_bug.cgi?id=579224
** Bug watch added: GNOME Bug Tracker #601410
https://bugzilla.gnome.org/show_bug.cgi?id=601410
--
You received this bug notification because you are a member of Desktop
Packages, which is subscribed to gnome-power-manager in Ubuntu.
https://bugs.launchpad.net/bugs/527157
Title:
Brightness controls skips Levels.
Status in “gnome-power-manager” package in Ubuntu:
Triaged
Status in “gnome-power-manager” package in Arch Linux:
New
Bug description:
Binary package hint: gnome-power-manager
Expected:
Hitting brightness up key or brightness down key changes brightness by one
level out of 15.
Actual:
Hitting brightness up key or brightness down key changes brightness by two or
three levels out of 15.
When I use the brightness control keys from a fresh install, the brightness
jumps THREE increments.
By creating /etc/modprobe.d/video.conf and setting
options video brightness_switch_enabled = 0
I reduce this to consistently TWO brightness events, but this is still double
the normal events. If I kill gnome-power-manager, it returns to single
brightness events.
when hitting brightness up/down with gnome-power-manager, udevmonitor shows
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent
KERNEL[1267026969.897008] change /devices/virtual/backlight/acpi_video0
(backlight)
UDEV [1267026969.898270] change /devices/virtual/backlight/acpi_video0
(backlight)
KERNEL[1267026969.903078] change /devices/virtual/backlight/acpi_video0
(backlight)
UDEV [1267026969.903842] change /devices/virtual/backlight/acpi_video0
(backlight)
KERNEL[1267026971.355970] change /devices/virtual/backlight/acpi_video0
(backlight)
UDEV [1267026971.357418] change /devices/virtual/backlight/acpi_video0
(backlight)
with gnome-power-manager not running, it shows no events.
Before:
cat /proc/acpi/video/IGD0/LCD/brightness
levels: 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
current: 25
Brightness up pressed:
cat /proc/acpi/video/IGD0/LCD/brightness
levels: 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
current: 40
With options video brightness_switch_enabled = 0:
cat /proc/acpi/video/IGD0/LCD/brightness
levels: 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
current: 25
Brightness up pressed:
cat /proc/acpi/video/IGD0/LCD/brightness
levels: 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
current: 35
With brightness_switch_enabled=0 and gnome-power-manager not running:
cat /proc/acpi/video/IGD0/LCD/brightness
levels: 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
current: 25
Brightness up pressed:
cat /proc/acpi/video/IGD0/LCD/brightness
levels: 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
current: 30
Description: Ubuntu lucid (development branch)
Release: 10.04
xserver-xorg-video-intel:
Installed: 2:2.9.1-1ubuntu1
Candidate: 2:2.9.1-1ubuntu1
Version table:
*** 2:2.9.1-1ubuntu1 0
500 http://archive.linux.duke.edu lucid/main Packages
100 /var/lib/dpkg/status
gnome-power-manager:
Installed: 2.29.1-0ubuntu2
Candidate: 2.29.1-0ubuntu2
Version table:
*** 2.29.1-0ubuntu2 0
500 http://archive.linux.duke.edu lucid/main Packages
100 /var/lib/dpkg/status
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/527157/+subscriptions
--
Mailing list: https://launchpad.net/~desktop-packages
Post to : [email protected]
Unsubscribe : https://launchpad.net/~desktop-packages
More help : https://help.launchpad.net/ListHelp
