Re: [RFC] PM: Add PM_RESUME_PREPARE and PM_POST_RESUME notifiers

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

On Tuesday, 30 October 2007 15:52, Alan Stern wrote:
> On Mon, 29 Oct 2007, Rafael J. Wysocki wrote:
> 
> > On Monday, 29 October 2007 22:30, Alan Stern wrote:
> > > Rafael:
> > > 
> > > How does this patch look?  Any reason not to have the resume notifiers?  
> > 
> > Yes.
> > 
> > The userland interface already uses PM_HIBERNATION_PREPARE and
> > PM_POST_HIBERNATION for restore too, so if anything, we should call these
> > from software_resume() either.
> 
> I could use those same notifiers, but are you sure that's a good idea?  

I'm not sure, but also I have no counter examples.

> Drivers might want to do different things at the beginning of
> hibernation and the beginning of a restore.
> 
> Alternatively, the user interface can be changed.  The current 
> organization is slightly illogical; there should be different ioctls 
> for prepare-to-create-snapshot and prepare-to-restore-snapshot instead 
> of a single SNAPSHOT_FREEZE for both.  How about adding RESTORE_FREEZE 
> and RESTORE_UNFREEZE; does this sound good?

Hm, we could define separate FREEZE ioctls for restore, but if they end up
doing the same as the analogous snapshot ones, they'll be somewhat redundant
...

> Alan Stern
> 
> P.S.: While I'm updating things, the thought occurs that 
> PM_RESTORE_PREPARE and PM_POST_RESTORE would be better names than 
> PM_RESUME_PREPARE and PM_POST_RESUME.

Agreed.

Greetings,
Rafael