[linux-pm] [RFD] Automatic suspend

[Rafael J. Wysocki]

On Friday 27 February 2009, Alan Stern wrote:
> On Fri, 27 Feb 2009, Pavel Machek wrote:
> 
> > 
> > > To summarize, we can:
> > > * Use a refcount such that automatic suspend will only be possible if it's
> > >   equal to zero (but that need not be the only criterion).
> > > * Use a per-device flag in dev_pm_info that will be set whenever the device
> > >   driver increases the refcount and unset whenever the driver decreases the
> > >   refcount.
> > > * Use a per-process flag that will be set whenever the process increases the
> > >   refcount and unset whenever the process decreases the refcount.
> > 
> > Yes, that sounds sane, and that's how reasonable wakelock
> > implementation should look like.
> 
> One small point: If you add a per-device flag and a per-process flag as 
> described above, then drivers and processes must not acquire nested 
> references.
> 
> Obviously this is fixable, but it's worth mentioning...

Yes, it's important to remeber IMO.

Thanks,
Rafael