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

Alan Cox alan at
Sun Sep 5 04:28:49 PDT 2004

On Sul, 2004-09-05 at 08:47, Alan Coopersmith wrote:
> 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.

The synchronization of clients is easy wit DRI. The actual restore
sequences for video chips are often closely guarded secrets, and on many
systems only the BIOS even knows what the analogue hardware looks like.

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