[GIT PULL] On-demand device probing

[Alan Stern]

On Tue, 20 Oct 2015, Mark Brown wrote:

> On Tue, Oct 20, 2015 at 10:40:03AM -0400, Alan Stern wrote:
> 
> > Furthermore, that applies only to devices that use synchronous suspend.  
> > Async suspend is becoming common, and there the only restrictions are 
> > parent-child relations plus whatever explicit requirements that drivers 
> > impose by calling device_pm_wait_for_dev().
> 
> Hrm, this is the first I'd noticed that feature though I see the initial
> commit dates from January.

Async suspend and device_pm_wait_for_dev() were added in January 2010, 
not 2015!

>  It looks like most of the users are PCs at
> the minute but we should be using it more widely for embedded things,
> there's definitely some cases I'm aware of where it will allow us to
> remove some open coding.
> 
> It does seem like we want to be feeding dependency information we
> discover for probing way into the suspend dependencies...

Rafael has been thinking about a way to do this systematically.  
Nothing concrete has emerged yet.

Alan Stern