On Tuesday, April 26, 2011, Pavel Machek wrote: > Hi! > > > > > What is the root problem that this is trying to solve? > > > > > > It is trying to fix machines that need to run periodic kernel tasks > > > even when user asked them to sleep. Zaurus needs to periodicaly wake > > > up to be able to charge battery in s2ram state, for example. > > > > Well, if you wake up periodically, it's not S2RAM any more, I'd say. > > It certainly looks a lot like s2ram to the user. > > Now, your PC wakes up periodically in s2ram, too; but it is keyboard > controller that wakes up, not CPU, so you do not know. I seriously doubt it's a keyboard controller in contemporary machines. Yes, there are parts of them that don't actually sleep, but that's not under OS control. > On Zaurus, you do not know, either; nothing visible happens and > userspace is shielded from these details. If you wake up device drivers, it _is_ visible. Maybe not to user space, but that's a semantic difference. > Should user really have to know if battery charger is implemented on > keyboard controller or on main cpu before he selects which interface > to use? Please don't confuse user space with the user. You can resume all the way to user space without turning the backlight on and the user will not notice, right? Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
