Hi! > > > The theoretical answer is that it behaves the way we want. The kernel > > > thread does selective resumes in response to device requests. If such > > > a request comes in while the system is asleep it will awaken the > > > system; so it's only logical that a request coming in while the system > > > is in the process of going to sleep should abort the suspend. > > > > I'd say that it shows ppc being broken. User wanted to suspend the > > system, and now unrelated task did lsusb... and system will not sleep. > > > > AFAICT it is DoS issue -- if one of your users keeps doing lsusb, root > > will not be able to suspend the system. > > This is a matter of one's philosophy. In suspend-to-RAM, should tasks > be frozen or should I/O queues be frozen? > > With the USB subsystem I have followed the approach taken by the PM > core, which is that tasks are frozen. But one can -- and Linus has on > at least one occasion -- make a good case that tasks should be left > running while only I/O is frozen. This would require the subsystem to > distinguish between a selective device suspend and a system-wide > suspend-to-RAM, so that selective resume could be enabled on demand in > one case but not the other. > > It's quite doable in principle -- it's just not the technique I used. I guess we need to do that. Random user should not be able to prevent machine from sleeping. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
