Hi!
> +Suspend notifiers
> + (C) 2007 Rafael J. Wysocki <[EMAIL PROTECTED]>, GPL
> +
> +There are some operations that device drivers may want to carry out in their
> +.suspend() routines, but shouldn't, because they can cause the hibernation or
> +suspend to fail. For example, a driver may want to allocate a substantial
> amount
> +of memory (like 50 MB) in .suspend(), but that shouldn't be done after the
> +swsusp's memory shrinker has run.
> +
> +Also, there may be some operations, that subsystems want to carry out before
> a
> +hibernation/suspend or after a restore/resume, requiring the system to be
> fully
> +functional, so the drivers' .suspend() and .resume() routines are not
> suitable
> +for this purpose. For example, device drivers may want to upload firmware to
> +their devices after a restore from a hibernation image, but they cannot do
> it by
> +calling request_firmware() from their .resume() routines (user land processes
> +are frozen at this point). The solution may be to load the firmware into
> +memory before processes are frozen and upload it from there in the .resume()
> +routine. Of course, a hibernation notifier may be used for this purpose.
> +
> +The subsystems that have such needs can register suspend notifiers that will
> be
> +called upon the following events by the suspend core:
> +
> +PM_PRE_FREEZE The system is going to hibernate or suspend,
> tasks will
> + be frozen immediately
Hmm, looks like bad idea if we are going to remove freezer from
suspend...?
> +PM_POST_THAW Tasks have just been thawed after a resume or restore
> + from a hibernation image
> +
> +PM_HIBERNATION_PREPARE The system is preparing for hibernation. Tasks
> have
> + been frozen, memory is going to be freed and devices
> + are going to be suspended.
Is not PRE_FREEZE enough? We can allocate memory for drivers there,
too...
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures)
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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