Re: System sleep vs. runtime PM

Oliver Neukum
2009-12-03T20:11:30Z

Am Donnerstag, 3. Dezember 2009 20:52:15 schrieb Alan Stern:

> That's not necessarily so. If remote wakeup is disabled at a device
> between the CPU and the source device, then wakeup events are indeed
> allowed to get lost. For example, even though a USB hub may be enabled
> for remote wakeup, if its host controller isn't then a wakeup event
> won't generate an IRQ and so won't awaken the system. And in fact this
> behavior may be desired by the user. After all, who would want their
> laptop to wake up merely because a USB mouse was unplugged?

That is no problem while the system is asleep. It is no good once the system
wakes up.

> > But the core doesn't
> > know specifics. Unless you really want to overengineer this and compute
> > the reliability of each path, resuming only those whose drivers have
> > requested that remote wakeup be enabled is the best you can do.
>
> Isn't that what I agreed drivers should do?

If the algorithm is clear and based only on remote wakeup, why
would you want to involve drivers?

I am afraid we are having a misunderstanding. Could you elaborate?

Regards
Oliver