Re: PCI PM & compatibility

[Patrick Mochel <mochel@osdl.org>]

> > - When a device is suspended, the pm_users count of its pm_parent is 
> >   decremented, and incremented when the device is resumed. 
> > 
> > - device_suspend() makes multiple passes over the device list, in case
> >   power dependencies cause some devices to be deferred. It fails with an 
> >   error (and resumes all suspended devices) if a pass was made in which 
> >   no devicse were suspended, but there are still devices with a positive
> >   pm_users count. 
> 
> How do you intend to deal with the childs of the device that has
> pm_users non null ?
> 
> If you don't suspend it, you must also postpone all of it's childs.
> That makes the list walking slightly more tricky, or you finally go
> to a real tree structure ? (Which you may have to do to implement
> the set_parent() thing too, no ?

I don't understand. We suspend the children before we suspend the device, 
so as long as all the children go done, so will the parent device.


	Pat