[ltp] Xorg radeon vs. CPU powerstate

[Alex Deucher]

On 2/21/07, Joachim Breitner <mail@joachim-breitner.de> wrote:
> Hi,
>
> although I'm close to getting rid of my T41p, I finally investigated my
> CPU's power state. Under my normal working conditions the CPU stays in
> C2 all the time. Neither unloading USB, wireless or GNOME changes that.
> But what does change it is to switch from Xorg (w/radeon driver) to the
> console, while everything else might be running. Then the C3 state (and
> even C4 which only exists when I am on battery) is used at least a bit.
> So I suspect that the free radeon driver is to blame.
>
> Is this known? Does it happen to others as well? Is there a fix?
>

This is a known issue.  When the command processor in the radeon is
active (i.e., DRI enabled), there is bus master activity, so the
machine cannot enter C3.

Alex


> Thanks,
> Joachim
>