Re: Async suspend-resume patch w/ completions (was: Re: Async suspend-resume patch w/ rwsems)

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Sunday 20 December 2009, Linus Torvalds wrote:
> 
> On Sun, 20 Dec 2009, Rafael J. Wysocki wrote:
> > > 
> > > Why would it be?
> > 
> > The embedded controller may depend on it.
> 
> Again, I say "why?"
> 
> Anything can be true. That doesn't _make_ everything true. There's no real 
> reason why PnP/ACPI suspend/resume should really care.
> 
> We can try it. Not for 2.6.33, but by the 34 merge window maybe we'll have 
> a patch-series that is ready to be tested, and that aggressively tries to 
> do the devices that matter asynchronously.

Yes, I'd like to have such a patch series for 2.6.34.

So far I've been able to confirm that doing serio+i8042, USB and ACPI battery
asynchronously may give us significant time savings, especially during resume.

> So instead of you trying to make up some idiotic cross-device worries, 
> just see if those worries have any actual background in reality. So far I 
> haven't actually heard anything but "in theory, anything is possible", 
> which is such a truism that it's not even worth voicing.
> 
> That said, I still get the feeling that we'd be even better off simply 
> trying to avoid the whole keyboard reset entirely. Apparently we do it for 
> a few HP laptops. It's entirely possible that we'd be better off simply 
> not _doing_ the slow thing in the first place.

That very well may be the case, but I'm not the right person to confirm or deny
that.

Rafael