linux-kernel - Re: [2.6.25-rc1] System no longer powers off after shutdown

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Message-Id: <200802131955.53821.rjw@sisk.pl>
Date:	Wed, 13 Feb 2008 19:55:53 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Greg KH <gregkh@...e.de>
Cc:	Frans Pop <elendil@...net.nl>, linux-kernel@...r.kernel.org,
	linux-acpi@...r.kernel.org
Subject: Re: [2.6.25-rc1] System no longer powers off after shutdown

On Wednesday, 13 of February 2008, Greg KH wrote:
> On Wed, Feb 13, 2008 at 12:39:13PM +0100, Frans Pop wrote:
> > On Tuesday 12 February 2008, Greg KH wrote:
> > > On Tue, Feb 12, 2008 at 09:39:14PM +0100, Frans Pop wrote:
> > > > On Monday 11 February 2008, Frans Pop wrote:
> > > > > In general 2.6.25 if looking quite good on my desktop, but there's
> > > > > one important issue: the system no longer powers off after shutdown.
> > > > > This works fine with 2.6.24.
> > > >
> > > > Don't ask me why, but bisection shows this commit to be the cause of
> > > > the failure to power off:
> > > > commit c10997f6575f476ff38442fa18fd4a0d80345f9d
> > > > Author: Greg Kroah-Hartman <gregkh@...e.de>
> > > > Date:   Thu Dec 20 08:13:05 2007 -0800
> > > >
> > > >     Kobject: convert drivers/* from kobject_unregister() to
> > > > kobject_put()
> > > >
> > > > Because it seemed somewhat unlikely, I have double checked this by
> > > > doing an extra compilation for this commit and its predecessor.
> > >
> > > What is the symptom of not powering off?
> > 
> > I already noticed yesterday that there's one hunk in that commit that's not
> > a straight replacement:
> > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> > index 9e102af..5efd555 100644
> > --- a/drivers/cpufreq/cpufreq.c
> > +++ b/drivers/cpufreq/cpufreq.c
> > @@ -1030,8 +1030,6 @@ static int __cpufreq_remove_dev (struct sys_device * sys_dev)
> > 
> >         unlock_policy_rwsem_write(cpu);
> > 
> > -       kobject_unregister(&data->kobj);
> > -
> >         kobject_put(&data->kobj);
> > 
> >         /* we need to make sure that the underlying kobj is actually
> > 
> > 
> > So, just on the off chance, I applied the patch below and bingo, the system
> > powers off again. I doubt this will be the correct solution, but just in
> > case it is, here's my signed off. A comment why the double put is needed
> > would probably be good though.
> 
> There is a bug in the cpufreq kref logic that makes this "double put"
> necessary.  A real fix has already been posted to solve this issue, and
> I think it should be on it's way to Linus for -rc2 already.
> 
> Please let me know if -rc2 comes out without this needed fix.

Can you point me to the fix, please?

Thanks,
Rafael
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