On Friday, July 02, 2010, Pavel Machek wrote: > On Thu 2010-07-01 21:02:27, Rafael J. Wysocki wrote: > > On Thursday, July 01, 2010, Pavel Machek wrote: > > > Hi! > > > > > > > @@ -114,3 +114,17 @@ Description: > > > > if this file contains "1", which is the default. It may be > > > > disabled by writing "0" to this file, in which case all devices > > > > will be suspended and resumed synchronously. > > > > + > > > > +What: /sys/power/wakeup_count > > > > +Date: July 2010 > > > > +Contact: Rafael J. Wysocki <rjw@xxxxxxx> > > > > +Description: > > > > + The /sys/power/wakeup_count file allows user space to avoid > > > > + losing wakeup events when transitioning the system into a sleep > > > > + state. Reading from it returns the current number of registered > > > > + wakeup events and it blocks if some wakeup events are being > > > > + processed at the time the file is read from. Writing to it > > > > + will only succeed if the current number of wakeup events is > > > > + equal to the written value and, if successful, will make the > > > > + kernel abort a subsequent transition to a sleep state if any > > > > + wakeup events are reported after the write has returned. > > > > > > I assume that second suspend always succeeds? > > > > The mechanism is one-shot if that's what you're asking for. > > Yep, it would be nice to document it. > > Plus maybe... should there be way to clear the wakeup_count? For > example when userspace decides that battery is low and that it wants > to go to sleep now? You don't need to clear it, just don't write to it before writing to /sys/power/state. Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
