On Wed, 3 Nov 2004, Benjamin Herrenschmidt wrote: > > What if it's known that the device is frozen but the parent isn't? Then > > there would be no problem. > > That never happens unless we do partial tree or that sort of thing. That's exactly what happens with device PM and autosuspend. > > How can it be illegal for the PM core to ask frozen devices to make > > transitions if it doesn't know whether or not they are frozen (i.e., if > > the dev->power.power_state field is gone)? > > I think we must keep that knowledge, though power_state is a bad name > for it, at least as an information for us, especially if we do partial > tree suspend. It's worth thinking about what should happen during a system suspend when some individual devices are already powered down. If possible we would like to avoid powering them back up just in order to turn them off again. Alan Stern
