Re: [patch update 3] PM: Introduce core framework for run-time PM of I/O devices

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Monday 22 June 2009, Alan Stern wrote:
> On Mon, 22 Jun 2009, Rafael J. Wysocki wrote:
> 
> > > Again, this boils down to how drivers decide to use the async 
> > > interface.  I can see justifications for both pm_request_resume_get 
> > > (which would always increment the counter) and pm_request_resume (which 
> > > would increment the counter only if a work item had to be queued).
> > 
> > OK, so this means we should provide both at the core level and let the drivers
> > decide which one to use.
> > 
> > I think in both cases the caller would be responsible for decrementing the
> > counter?
> 
> Sure.  They could call pm_runtime_put just once at the end of their
> runtime_resume method (assuming they used pm_request_resume), or they
> could call it at every place where some deferred work was finished 
> (assuming they used pm_request_resume_get).
> 
> > > Okay, we don't need it then.  I forgot to mention in the previous
> > > message that there also has to be a pm_runtime_del() routine, which
> > > should cancel pending workqueue items and set the counter to some high
> > > value so that no new items are added.
> > 
> > Should that be called by device_pm_remove()?  I think so.
> 
> Yes.  I suppose it could be named pm_runtime_remove.  Either would be 
> okay.

OK

I'm sending a new version of the $subject patch, containing these changes
among other things, in a new thread.

Best,
Rafael