Re: [linux-pm] pm_runtime_suspended() and non-pm_runtime-using (i2c) drivers

[Mark Brown <broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>]

On Tue, Dec 14, 2010 at 06:03:06PM -0500, Alan Stern wrote:
> On Tue, 14 Dec 2010, Mark Brown wrote:

> > When I've been working with the runtime PM subsystem before I've thought
> > that it might be nice to have a specific RPM_UNINITIAZLIZED state which
> > would generally get out of the way.  It might be a bit clearer than the

> That's an interesting suggestion.  In general the PM core can't tell 
> what power state a device is really in when it is first discovered and 
> registered.

> I don't know if it would really solve your problem, though.  What we 
> really need is a better way to tell when a device shouldn't prevent its 
> parent from suspending.  Something like: If a device has no driver and 
> no children, it should automatically be put in the RPM_SUSPENDED state.

Yes, there'd need to be a bunch of code implementing behaviours that
look like what you suggest above and I'm not clear if it'd be worth the
hassle of implementing it - like I say, I'm not generally comfortable
enough with my understanding in this area to have a strong opinion on
the best approach.