James: no, there is no need to touch kernel. You should have noticed, that brightness control works as expected, before you login (during boot or even on login screen).
Problem is in user-level process running during user session. We have to find that process, than fix will be pretty simple. See plugins/media-keys/gsd-media-keys-manager.c:1528, function do_screen_brightness_action_real(): looks like it is correct place for patch. Later I will think on good solution. -- 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
