Frame Buffer Power Management / was: Re: The ati petition

[Alan Coopersmith]

Roland Mainz wrote:
> s/X/Xorg,Xfree86/ ... Sun has fully functional power managment for their
> own graphics cards (search http://docs.sun.com/ for "FBPM" (="Frame
> Buffer Power Management")) for their own cards.

Only for some cards (UPA bus only I think, not PCI).

> The question is whether their implementation can be ported to Xorg...

The core X server part is easy - that's basically DPMS with the function
names changed.  The hard parts are in the OS specific power management
interfaces, the drivers for each card and the kernel.  From the experience
we had at Sun I can tell you that it's not always simple to save all state
from the card to main memory at power off, then restore it at power on, and
if any programs are bypassing the server to talk directly to the card using
DGA/DRI type technologies, it may not be possible at all.

-- 
	-Alan Coopersmith-           alan.coopersmith at sun.com
	 Sun Microsystems, Inc. - X Window System Engineering