Re: [PATCH] x86: Add reboot quirk for Dell Precision M4600

Ingo Molnar
2011-08-09T15:03:18Z

* Bruno Friedmann <bruno@ioda-net.ch> wrote:

> On 08/08/2011 06:40 PM, H. Peter Anvin wrote:
> > On 08/06/2011 10:30 AM, Matthew Garrett wrote:
> >> On Sat, Aug 06, 2011 at 08:56:35AM +0200, Ingo Molnar wrote:
> >>> Weird - ACPI is the default Windows method of reboot - how come it
> >>> does not work on that box? Does Windows work around this specific
> >>> machine (unlikely), or is our ACPI boot sequence not 100% compatible
> >>> with the Windows method (more likely IMO)?
> >>
> >> The ACPI reboot method on these machines hits the keyboard controller
> >> rather than PCI, which is unusual. What I suspect is that the write
> >> triggers some SMM or EC code that's making assumptions about system
> >> state, and we're not quite identical. Bouncing on the keyboard
> >> controller from userspace with init=/bin/bash wedges in the same way.
> >>
> >
> > I have a vague suspicion that Windows might have a meta-quirk for this
> > class of machines, i.e. if the ACPI reboot method, say, points at the
> > keyboard controller or points at the "PCI" reboot port then it actually
> > uses its own special-purpose routines rather than general routines. It
> > would be extremely interesting to know if "reboot=kbd" works on these boxen.
> >
> > -hpa
> >
>
> Test done with reboot=pci and unfortunately doesn't work.

Didn't hpa suggest reboot=kbd?

Thanks,

Ingo