Re: Linux 2.6.27-rc5: System boot regression caused by commit a2bd7274b47124d2fc4dfdb8c0591f545ba749dd

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Friday, 29 of August 2008, Rafael J. Wysocki wrote:
> On Friday, 29 of August 2008, Linus Torvalds wrote:
> > 
> > Another week (my weeks do seem to be eight days, don't they? Very odd), 
> > another -rc.
> > 
> > The dirstat pretty much says it all:
> > 
> >   43.0% arch/arm/configs/
> >   43.9% arch/arm/
> >   25.5% arch/powerpc/configs/
> >   26.8% arch/powerpc/
> >   73.9% arch/
> >    4.4% drivers/usb/musb/
> >    5.4% drivers/usb/
> >    4.0% drivers/watchdog/
> >   16.0% drivers/
> >    3.5% fs/
> > 
> > yeah, the bulk of it is all config updates, and with arm and powerpc 
> > leading the pack.
> 
> Doesn't boot on my quad core test box, apparently because of an AHCI failure.
> 
> Bisecting ...

Bisection turned up commit a2bd7274b47124d2fc4dfdb8c0591f545ba749dd as the culprit:

commit a2bd7274b47124d2fc4dfdb8c0591f545ba749dd
Author: Yinghai Lu <yhlu.kernel@gmail.com>
Date:   Mon Aug 25 00:56:08 2008 -0700

    x86: fix HPET regression in 2.6.26 versus 2.6.25, check hpet against BAR, v3

Reverting this commit helps.

The symptom is that AHCI probe fails with this commit applied.

Thanks,
Rafael