[linux-pm] [RFC][PATCH] PM: Introduce new top level suspend and hibernation callbacks (rev. 2)

[Rafael J. Wysocki]

On Tuesday, 25 of March 2008, Oliver Neukum wrote:
> Am Freitag, 21. März 2008 01:21:03 schrieb Johannes Berg:
> > > + * All of the above callbacks, except for @complete(), return error codes.
> > > + * However, the error codes returned by the resume operations, @resume(),
> > > + * @thaw(), and @restore(), are only printed in the system logs, since the PM
> > > + * core cannot do anything else about them.
> > 
> > Why bother and not just make them return void, the error printing can
> > most likely be done much much better in the callback since that possibly
> > has information on why it failed.
> 
> A device that cannot wake up is unusable. Shouldn't the pm core disconnect()
> such a device?

Well, if ->resume() returns an error, the driver already knows there's a
problem and it can act upon that, at least in principle.

However, the PM core probably shouldn't try to resume the children of a failing
device.  Also, if ->resume_noirq() fails, it probably is not a good idea to
call ->resume() and ->complete() for the same device and for it's children.

Thanks,
Rafael