On Sun, 2011-07-31 at 15:37 -0300, Sergio Belkin wrote:
> I've read
http://fedoraproject.org/wiki/Bugs/Common#Laptop_screen_dims_when_switchi...
>
> My system suffers the same symptoms but I use KDE. So it seems that is
> not GNOME restricted.
>
>
> Using F15 on x86_64
>
> cat /sys/module/pcie_aspm/parameters/policy
> default performance [powersave]
>
> any ideas?
That bug certainly was GNOME specific: it was a bug in
gnome-power-manager 's logic. There's no way that specific bug could
affect KDE, unless somehow you're running g-p-m in KDE. If you're seeing
a similar issue in KDE, it must track down to a different bug, so please
file it. Be aware, though, that the display dimming somewhat when you
disconnect the AC power is 'normal': both KDE and GNOME do this to save
battery power. The bug in this case was that when you re-connected to AC
the brightness did not increase again, but if you then disconnected from
AC once more the brightness would decrease further - so you got stuck in
a descending spiral of darkness until the screen was stuck at its lowest
possible brightness setting until you adjusted it manually or rebooted.
If the screen dims somewhat (to, say, 50%) when you unplug, goes back up
to 100% when you plug back in, then dims back to 50% when you unplug
again, that's intended behaviour and not a bug (though if you don't like
it, it's configurable).
I've seen a different bug on KDE - specifically - after a sleep/resume
cycle (I think) - going to battery off A/C - the applet says its in
powersave mode but the screen is NOT dimmed - using the applet to switch
to performance and then back to powersave mode - dims the screen.
This is (as far as I know) specific to KDE but I could be wrong ...