Re: Re: Possible problem with device_move()

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Wed, 1 Aug 2007 11:22:12 -0400 (EDT),
Alan Stern <stern@rowland.harvard.edu> wrote:

> As it stands right now, every place device_move() gets called is 
> already special!

The "special cases" I was thinking about are those where the order to
suspend/resume is not covered by a parent/child relationship, but by
(possibly random) order of registration. I'd have thought the rule "the
child must be suspended before the parent" was pretty straightforward,
but...
> 
> I'm afraid of reordering devices automatically; there's too much 
> potential for creating new problems.  When a driver calls device_move() 
> or does something similar, it should know what sort of list 
> rearrangement is safe.  But the PM core can't be expected to know.

...you have a point here. Automatic reordering may destroy other
ordering, so we shouldn't do it.

(The whole list based on registration order thing seems a bit fragile
to me, but I don't know enough of the PM core and suspend/resume in
general to make a better suggestion :/)