Re: 2.6.18-rc4 (and earlier): CMOS clock corruption during suspend to disk on i386

Rafael J. Wysocki
2006-08-09T20:52:57Z

On Wednesday 09 August 2006 22:12, Andrew Morton wrote:
> On Wed, 9 Aug 2006 22:01:42 +0200
> "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>
> > On Wednesday 09 August 2006 14:30, Pavel Machek wrote:
> > > Hi!
> > > >
> > > > It looks like the CMOS clock gets corrupted during the suspend to disk
> > > > on i386. I've observed this on 2 different boxes. Moreover, one of them is
> > > > AMD64-based and the x86_64 kernel doesn't have this problem on it.
> > > >
> > > > Also, I've done some tests that indicate the corruption doesn't occur before
> > > > saving the suspend image. It rather happens when the box is powered off
> > > > or rebooted (tested both cases).
> > > >
> > > > Unfortunately, I have no more time to debug it further right now.
> > >
> > > Do you have Linus' "please corrupt my cmos for debuggin" hack enabled?
> >
> > Well, I know nothing about that. ;-)
> >
>
> CONFIG_PM_TRACE=y will scrog your CMOS clock each time you suspend.

Oh dear. Of course it's set in my .config. Thanks a lot for this hint. :-)

BTW, it's a dangerous setting, because some drivers get mad if the time after
the resume appears to be earlier than the time before the suspend. Also the
timer .suspend/.resume routines aren't prepared for that.