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Subject: Re: Calling suspend() in halt/restart/shutdown -> not a good idea
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Machek <pavel@ucw.cz>, Andrew Morton <akpm@osdl.org>,
       Linux Kernel list <linux-kernel@vger.kernel.org>
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Date: Wed, 03 Aug 2005 13:43:07 +0200
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On Tue, 2005-08-02 at 08:40 -0600, Eric W. Biederman wrote:
> Pavel Machek <pavel@ucw.cz> writes:
> 
> > Hi!
> >
> >> Why are we calling driver suspend routines in these ? This is _not_
> >
> > Well, reason is that if you remove device_suspend() you'll get
> > emergency hard disk park during powerdown. As harddrives can survive
> > only limited number of emergency stops, that is not a good idea.
> 
> Then the practical question is: do we suspend the disk by
> calling device_suspend() for every device.  Or do we modify
> the ->shutdown() method for the disk.

afaik, IDE used to have a shutdown callback or a shutdown notifier
already anyway. If that was lost, then this is a different problem. If
SATA and/or SCSI aren't doing it, then they need fixing, but suspend()
isn't the solution.

Ben.