[ltp] X31 - DRI prevents CPU from going to C3 powersaving state

[Michael Kamper]

Hi,

I'm quite happy with my X31 and I even made DRI (3D-acceleration) work.
Now there is just one annoying thing: When I enable DRI in xorg.conf with
       Load            "dri"
xorg will constantly cause bus master activity thus preventing the cpu
enter the C3 powersaving state.

C3 in
/proc/acpi/processor/CPU/power
will never be entered!

When I disable dri in xorg, C3 is entered as usualy, giving me much more
battery life and cooler CPU. But this is not really an option, as I love
to use suspend2 and suspend to ram. So I wouldn't like to restart my
xserver every time I need 3D-acceleration.

Anybody has an idea how to solve this problem? I just don't see a reason
 for my idle X to cause bus master activity.

Yet some information: I'm using gentoo (stable) with xorg 6.8.2-r7
Kernel is 2.6.15

Regards
Michael