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

Yinghai Lu
2008-02-14T23:38:14Z

On Wed, Feb 13, 2008 at 8:58 AM, Greg KH <gregkh@suse.de> 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@suse.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.

after disable cpufreq, i got

ACPI: Preparing to enter system sleep state S5
Disabling non-boot CPUs ...
kvm: disabling virtualization on CPU1
CPU 1 is now offline
CPU1 is down
kvm: disabling virtualization on CPU2
CPU 2 is now offline
================> hang here.

but x86.git/mm could go through down all the cpus....

interesting...

YH