My laptop, a Dell Inspiron 4100, has a Radeon Mobility M6 graphics card. I've been using sarge on it with no problems for a long time, but since a few months back I've got sid running on my main workstation, and so I decided to put sid on the laptop too. Everything is fine, except for xorg. It eats *a lot* more cpu than xfree86 does on sarge, which makes the fans run constantly on the laptop. For instance, playing a dvd movie eats 67% cpu -- half of it used by xine, the other half by xorg. If I play the same thing in sarge, load is very low, especially on the xfree86 side.
This is all without dri. I can't seem to get dri working, no matter how I try. I've read loads of stuff on the net, and there seems to be others with the same problem. I can live without dri, but I can't live with xorg using that much cpu.
The problem is the same no matter what kernel I use. I've got bios revision a13 (the latest). Enabling/disabling
dri module doesn't change the load. Adding options like Accel On/off, AGPMode etc changes nothing either. Using the XF86Config-4 parameters in xorg.conf doesn't help either. Using a light windowmanager like fluxbox instead of gnome does next to nothing for the cpu load. I've got acpi turned off (doesn't work well with inspiron 4100), but enabling it changes nothing either.
I'm at a loss! Please help! I'm attaching X log and xorg.conf.