[linux-pm] [RFD] Automatic suspend

[Alan Stern]

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...

Alan Stern