This is more noticeable when using gnome-power-manager and changing the brightness using keys, but running xbacklight shows the problem as well: I get between .3 and .5 of a second running xbkaclight.
FYI, xbacklight: http://lwn.net/Articles/239261/
Bastien, you are aware of the -time and -steps argument to xbacklight?
Using: $ time ./xbacklight -steps 1 -time 0 -set 50 real 0m0.335s user 0m0.002s sys 0m0.003s I also modified xbacklight so backlight_set() is run directly, and no sleep() are done, and I still get a similar amount of time spent.
From "xrandr --prop": BACKLIGHT_CONTROL: combination supported: native legacy combination kernel BACKLIGHT: 156 (0x0000009c) range: (0,312) Using the "native" control (the only one that works other than combination), doesn't change the speed of setting the backlight, even when using xrandr to set it (eg. "xrandr --output LVDS --set BACKLIGHT 312").
XRRGetScreenResources() is the slow bit, takes 0.3 seconds.
Posted upstream: http://lists.freedesktop.org/archives/xorg/2008-May/035261.html
Yeah, i2c is slow alright.
Changing version to '9' as part of upcoming Fedora 9 GA. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
This message is a reminder that Fedora 9 is nearing its end of life. Approximately 30 (thirty) days from now Fedora will stop maintaining and issuing updates for Fedora 9. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as WONTFIX if it remains open with a Fedora 'version' of '9'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version prior to Fedora 9's end of life. Bug Reporter: Thank you for reporting this issue and we are sorry that we may not be able to fix it before Fedora 9 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora please change the 'version' of this bug to the applicable version. If you are unable to change the version, please add a comment here and someone will do it for you. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. The process we are following is described here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Fedora 9 changed to end-of-life (EOL) status on 2009-07-10. Fedora 9 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. Thank you for reporting this bug and we are sorry it could not be fixed.