Re: Runtime resume of children

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

On Monday 23 November 2009, Alan Stern wrote:
> On Mon, 23 Nov 2009, Rafael J. Wysocki wrote:
> 
> > On Sunday 22 November 2009, Alan Stern wrote:
> > > Rafael:
> > > 
> > > Here's the situation.  Device A has children B1, ..., Bn (possibly
> > > others too).  I need to guarantee that whenever A is active, so are the
> > > children.
> > 
> > But it's perfectly valid to have an inactive device under an active parent, so
> > I guess this is not a general case.
> 
> Correct.  It's a specific case that I need to handle for USB.
> 
> > > Do you have any ideas on how to approach this?  How about allowing A's
> > > runtime_resume method to set A->power.runtime_status to RPM_ACTIVE,
> > > before it tries to resume the B's?  That would avoid the deadlock.
> > 
> > I don't see a problem with that as long as the A's runtime_resume returns 0 in
> > such a case.
> 
> Should I export a routine from the PM core for doing this or just 
> implement it directly?

Please implement that directly.  If there's any other bus type needing it,
we'll move it to the core.

Thanks,
Rafael