Re: [RFD] Automatic suspend

Jesse Barnes
2009-02-17T22:19:13Z

On Tuesday, February 17, 2009 2:04 pm Matthew Garrett wrote:
> On Tue, Feb 17, 2009 at 01:57:17PM -0800, mark gross wrote:
> > Putting the wake on key event issue aside, is it possible to have wake
> > up's on the ms time scale? I ask because I thought the XO did exactly
> > this (but left the screen live). Why does it take 20 sec to get into
> > or out of S3 on my laptop?
>
> Graphics reinit, dumping graphics contents back into RAM, us resuming
> devices in series, that kind of thing. On some hardware you'll spend a
> noticable amount of time in the BIOS before any of the Linux resume code
> gets touched. I thought the XO had got sub second, but I wasn't sure
> that they were in the low ms range.

IME a good chunk of it is BIOS time. On my x200s resume is very fast (on the
order of a second or two though I haven't measured), while on my Eee and T61
machines it's much slower, even though they're all using Intel gfx.

Of course we should really be shooting for sub-second times or about the time
it takes you to open your lid (or even much faster in the case of demand
suspend/resume for servers/desktops).

--
Jesse Barnes, Intel Open Source Technology Center