https://bugzilla.novell.com/show_bug.cgi?id=692441 https://bugzilla.novell.com/show_bug.cgi?id=692441#c0 Summary: gnome-power-manager causes backlight flicker on MSI PR200 and other laptops Classification: openSUSE Product: openSUSE 11.4 Version: Final Platform: Other OS/Version: Other Status: NEW Severity: Major Priority: P5 - None Component: GNOME AssignedTo: bnc-team-gnome@forge.provo.novell.com ReportedBy: jmatejek@novell.com QAContact: qa@suse.de Found By: --- Blocker: --- when changing brightness (regardless of whether by keyboard or from some GUI control), the backlight will flicker wildly between the proposed and lowest setting. This also happens on gnome startup, because g-p-m is trying to set brightness to a predefined level and this also triggers the problem. The flicker usually stops after a second or two, but occassionally it goes on for more than five seconds. During that, the system doesn't seem to process keyboard events. Killing gnome-power-manager solves the problem. Redefining XF86MonBrightnessUp and XF86MonBrightnessDown events to no-ops (via xkb or xmodmap) and restarting g-p-m also fixes the problem. The backlight then can be changed through keyboard. (A minor drawback of both solutions is that g-p-m doesn't know about the brightness events and therefore doesn't display its brightness GUI. I can live with that, as opposed to killing my backlight ;) ) this is apparently fallout from a kernel change in 11.4 - i didn't try this, but reportedly downgrading the kernel solves the issue. Other distros (Ubuntu Natty, Fedora 15, Arch) have the same problem. Interestingly, OpenSUSE's behavior is slightly different, and best of the three: the flicker settles really quickly, whereas on the other distros it often continues for more than 15 seconds. here is a bugreport from ubuntu about the issue: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/756509 a related issue might be bug 498018 investigating with evtest discovers that every change to brightness triggers a keyboard "Brightness up" (or Down) event, even in cases where the change was made in software (e.g. echo 5 > /sys/class/backlight/acpi_video0/brightness). This leads me to believe that the problem is a race between g-p-m and kernel about changing the brightness level, and the underlying bug might be in the kernel. (i assigned this to gnome, though, because without g-p-m the problem doesn't exist) the severity is Major, because this behavior could in theory cause damage to the backlight -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.