Re: Spontaneous reboot of NetBSD/amd64 6.0_STABLE

[David Young <dyoung%pobox.com@localhost>]

On Thu, Mar 08, 2012 at 02:15:10PM +0300, Aleksey Cheusov wrote:
>  >> > my NetBSD/amd64 6.0_STABLE server just booted spontaneously. There is
>  >> > no trace in "dmesg" (why don't NetBSD/amd64 kernel messages survive
>  >> > reboots like they do under NetBSD/i386) and of course no crash dump.
>  >> 
>  >> A start would be to switch back to ddb on panic.
> 
> > Yes, I already did that. Let's see what happens next.
> 
> My amd64 system (workstation) also reboots spontaneously. Crash dump is
> not generated.  Is it possible to switch from graphical mode to text
> mode automatically before switching to ddb.

FWIW, on the amd64 machines (which ran i386 kernels, IIRC)
where I ported ixg(4), I saw not a spontaneous reboot but a
seemingly-spontaneous black screen and freeze until I found out that the
ixg(4)'s PCI registers were mapped prefetchable and fixed that.

It's apparently not that uncommon for PCI devices to ship with the
prefetchable BAR bit misprogrammed in their EEPROM.  Lots of our
PCI drivers will take the BAR at its word and blithely map the BAR
cached/write-combining/whatever.

Dave

-- 
David Young
dyoung%pobox.com@localhost    Urbana, IL    (217) 721-9981