kern/119675: [acpi] apic_hpet0 probe causes divide by
zero kernel panic
nate at root.org
Tue Jan 15 09:20:02 PST 2008
The following reply was made to PR kern/119675; it has been noted by GNATS.
From: Nate Lawson <nate at root.org>
To: Leo Bicknell <bicknell at ufp.org>
Cc: bug-followup at FreeBSD.org
Subject: Re: kern/119675: [acpi] apic_hpet0 probe causes divide by zero kernel
Date: Tue, 15 Jan 2008 08:48:14 -0800
Leo Bicknell wrote:
> In a message written on Tue, Jan 15, 2008 at 10:13:07AM -0500, John Baldwin wrote:
> > You can try the patch below. It fixes a couple of places where we don't
> > honor the spec (we don't shut it off in S1 and S2 as required and we don't
> > preserve reserved bits in the global configuration register). It also
> > fails the attach if the period is zero which should fix your panic and
> > just leave you with no HPET.
> Good news and bad news.
> With the patch "invalid period" is printed out, so I believe it's
> correctly detecting the hpet0 issue.
> However, I immediately get an "integer divide fault while in kernel
> mode" panic and the boot still fails. I tried with boot -v and the
> message is right after the "invalid period", so I'm not quite sure
> what's causing it.
> Any recomendations, other than setting up a kernel debugger to see where
> it's coming from?
John's patch should be committed anyway. However, it's possible your
panic is happening in non-acpi code. There's no way to narrow it down
perfectly without enabled the debugger (options DDB etc.) and typing
"trace" after it panics.
However, a boot verbose (boot -v) may give a little more information.
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