From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Patrick Mochel <mochel@osdl.org>
Cc: Russell King <rmk@arm.linux.org.uk>, Greg KH <greg@kroah.com>,
       linux-kernel mailing list <linux-kernel@vger.kernel.org>
In-Reply-To: <Pine.LNX.4.33.0308260817190.942-100000@localhost.localdomain>
References: <Pine.LNX.4.33.0308260817190.942-100000@localhost.localdomain>
Message-Id: <1061988185.1293.57.camel@gaston>
Mime-Version: 1.0
Date: Wed, 27 Aug 2003 14:43:06 +0200
Subject: Re: PCI PM & compatibility
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1035
Lines: 27


> 
> - When a device is suspended, the pm_users count of its pm_parent is 
>   decremented, and incremented when the device is resumed. 
> 
> - device_suspend() makes multiple passes over the device list, in case
>   power dependencies cause some devices to be deferred. It fails with an 
>   error (and resumes all suspended devices) if a pass was made in which 
>   no devicse were suspended, but there are still devices with a positive
>   pm_users count. 

How do you intend to deal with the childs of the device that has
pm_users non null ?

If you don't suspend it, you must also postpone all of it's childs.
That makes the list walking slightly more tricky, or you finally go
to a real tree structure ? (Which you may have to do to implement
the set_parent() thing too, no ?

Ben.


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/