radeon driver stops C3 if DRI is enabled

[Lorenzo C. <lo...@co...>]

Hi,

I saw this reported on the acpi list too [1], so I thought I would post 
it here hoping it's the right place to send it.

Using the radeon driver from recent X.org CVS (on Linux 2.6.11.10), my 
CPU never enters C3 while under X. This causes me to lose about 30 
minutes of battery life.

This is due to the radeon driver causing bus master activity: if I 
switch to a text console C3 starts getting used again, and if drm.ko is 
not available when X starts (or if dri is disabled [1]), the CPU enters 
C3 under X too.

Is there something that can be done to fix this?


Cheers,
Lorenzo

[1] 
http://sourceforge.net/mailarchive/forum.php?thread_id=7785754&forum_id=6102