Am Mittwoch, 26. März 2008 15:10:01 schrieb Alan Stern: > > > IMO you must always keep the ordering invariant. If a parent returns an error > > > the PM core must not wake its children. > > Don't think of it that way. The PM core doesn't wake anything. It > merely notifies drivers that the system sleep is ending, so that the > drivers can wake their devices. It's up to the driver to detect > whether the parent failed to resume, in which case the driver should > take appropriate action. How do you propose that every driver should check the power state of its parent? Without locking the parent? > The situation is no different from what happens when the user tries to > access a mounted USB disk drive after the USB cable has been unplugged. > The drivers take care of everything. That completely throws away the reason to have a PM core. We've made a guarantee to drivers that they wil not be woken unless their parents are awake. In fact the semantics of the callbacks are defined in a way that adding devices to a parent can be enabled. You cannot add children to a dead parent. It's the very reason for this rewrite. Regards Oliver _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
