Re: [PATCH 2/2] Fix console handling during suspend/resume

Pavel Machek
2006-06-16T13:56:52Z

Hi!

> > Well, solving that problem is exactly why we have the PM callbacks in
> > bus hierarchy.
>
> No. That's a separate thing.
>
> We have PM callbacks in the bus hierarchy because we need that just to
> turn them off. You can't turn off the device after you've turned off the
> bus it is attached to.
>
> But that's _totally_ orthogonal to the issue that a complex state save may
> need a totally unrelated device - along dependancies we don't even _know_.
>
> For example, when a device save needs to allocate memory, that in turn can
> end up needing to write to just about _any_ device - and there simply _is_
> no hierarchy for that. No such hierarchy is even possible, because it's a
> circular problem.
>
> Btw, one final note:
>
> If people who do STD really do want to suspend all devices and then wake
> up devices that lead to the STD device, in the end, I personally simply
> don't care.

No, this is not what I want. I want to:

* freeze all devices (can be implemented as suspend)
* create atomic image
* unfreeze all devices (can be implemented as resume)
* write image to disk
* powerdown (which implies suspending devices).

...in fact, that is what we do today.

Pavel
--
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