Re: Patch: linux-2.5.42/kernel/sys.c - warm reboot should not suspend device

[ebiederm@xmission.com (Eric W. Biederman)]

"Adam J. Richter" <adam@yggdrasil.com> writes:

> Eric Blade wrote:
> >On Sun, 2002-10-13 at 15:24, Adam J. Richter wrote:
> >>        [...] I think the new behavior in IDE
> >> of spinning down the hard drives on suspend is correct.  The problem
> >> is that the warm reboot system call is trying to suspend all of the
> >> devices before a warm reboot for no reason.  [...]
> 
> >Adam,
> >  I'm not sure the proper thing to do is necessarily remove the
> >device_shutdown() call.
> 
> 	If, by this, you are saying that you have in mind some reason
> why this should not be done, then please explain.

We need it.  It doesn't make sense for every device driver
to register a reboot notifier.  When especially as they
have to run the same code when they are modular and are
removed.

Why would you not want to do that?

> >  Please try this patch [...]
> 
> 	Your patch does not apply and I don't see how renaming
> a constant in essentially every place that it is referenced would
> change the behavior of the code in a way releveant to the problem
> that I described.
> 
> 	I don't see a problem with device_shutdown spinning down the
> IDE hard disks.  What I have a problem with, and what my patch fixes,
> is the relatively new behavior of the warm reboot system call calling
> device_shutdown.  Why was this added?

Because most device drivers don't implement a reboot notifier?
And they almost certainly need it.

>   The reboot notifier chain is
> already called for devices that need some preparation before it is
> safe to reboot or halt.

Error please try again.  It is just they don't cause major problems
on reboot so no one notices the problems.

Eric