Re: [3/3] 2.6.21-rc7: known regressions (v2)

[john stultz <johnstul@us.ibm.com>]

On Wed, 2007-04-25 at 20:33 -0400, Len Brown wrote:
> On Wednesday 25 April 2007 14:08, john stultz wrote:
> > On Wed, 2007-04-25 at 04:06 -0700, Andrew Morton wrote:
> > > On Mon, 23 Apr 2007 23:49:09 +0200 Adrian Bunk <bunk@stusta.de> wrote:
> > > > Subject    : acpi_pm clocksource loses time on x86-64
> > > > References : http://lkml.org/lkml/2007/4/17/143
> > > > Submitter  : Mikael Pettersson <mikpe@it.uu.se>
> > > > Handled-By : John Stultz <johnstul@us.ibm.com>
> > > > Status     : problem is being debugged
> > 
> > 
> > The ACPI PM one is *really* odd as its the same clocksource driver on
> > both arches. I had Mikael cut out the clocksource frequency adjustments,
> > and confirmed both i386 and x86_64 are using the same base freq
> > (confirmed via printks).
> 
> If this chipset's PM-timer loses "several minutes per hour" on x86_64,
> I would expect it to do the same on i386.  I can't imagine what the
> difference could be.  Any possibility it is the 24-bit version
> and we do something funky on wraparound?

No, we assume the PM timer wraps at 24 bits and mask it as such on all
systems.

-john