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From: David Brownell <david-b@pacbell.net>
To: ncunningham@linuxmail.org
Subject: Re: Solving suspend-level confusion
Date: Wed, 4 Aug 2004 18:29:45 -0700
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       Oliver Neukum <oliver@neukum.org>, Pavel Machek <pavel@suse.cz>,
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       Patrick Mochel <mochel@digitalimplant.org>
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On Tuesday 03 August 2004 19:26, Nigel Cunningham wrote:

> > There's now some partial-tree code in CONFIG_USB_SUSPEND (for
> > developers only), but jumping from USB into the next level driver
> > (SCSI, video, etc) raises questions.
> 
> I've also done partial-tree support for suspend2 by making a new list
> (along side the active, off and off_irq lists) and simply moving devices
> I want to keep on (plus their parents) to this list prior to calling
> device_suspend. Works well for keeping alive the ide devices being used
> write the image.

What I'd need out of the PM framework would be "suspend this subtree",
and its cousin "resume this subtree".  Where the subtree starts with a
given device ... and, if it's got a driver, any abstract devices created
by that driver.  (And their children, etc.)

I'm not sure what to think about the desire of "suspend2" to prevent
a subtree from suspending.  In fact, I'm not at all sure how to even
interpret a "can't suspend" failure code... device in trouble, likely.

- Dave