On Tue, 22 Jun 2010, Rafael J. Wysocki wrote: > Anyway, below's an update that addresses this particular case. > > It adds two more functions, pm_wakeup_begin() and pm_wakeup_end() > that play similar roles to suspend_block() and suspend_unblock(), but they > don't operate on suspend blocker objects. Instead, the first of them increases > a counter of events in progress and the other one decreases this counter. > Together they have the same effect as pm_wakeup_event(), but the counter > of wakeup events in progress they operate on is also checked by > pm_check_wakeup_events(). > > Thus there are two ways kernel subsystems can signal wakeup events. First, > if the event is not explicitly handed over to user space and "instantaneous", > they can simply call pm_wakeup_event() and be done with it. Second, if the > event is going to be delivered to user space, the subsystem that processes > the event can call pm_wakeup_begin() right when the event is detected and > pm_wakeup_end() when it's been handed over to user space. Or if the event is going to be handled entirely in the kernel but over a prolonged period of time. > Please tell me what you think. I like it a lot. It addresses the main weakness in the earlier version. With this, you could essentially duplicate the in-kernel part of the wakelocks/suspend blockers stuff. All except the timed wakelocks -- you might want to consider adding a pm_wakeup_begin_timeout() convenience routine. Here's another possible enhancement (if you can figure out a way to do it without too much effort): After a suspend begins, keep track of the first wakeup event you get. Then when the suspend is aborted, print a log message saying why and indicating which device was responsible for the wakeup. One little thing: You have the PCI subsystem call pm_wakeup_event(). If the driver then wants to call pm_wakeup_begin(), the event will get counted twice. I guess this doesn't matter much, but it does seem peculiar. Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
