Re: IO-APIC on nforce2 [PATCH] + [PATCH] for nmi_debug=1 + [PATCH]for idle=C1halt, 2.6.5

From: Craig Bradney
Date: Thu Apr 15 2004 - 16:07:28 EST


On Thu, 2004-04-15 at 22:17, Len Brown wrote:
> On Thu, 2004-04-15 at 11:10, Ross Dickson wrote:
> > On Wednesday 14 April 2004 11:02, Len Brown wrote:
> > > Re: IRQ0 XT-PIC timer issue
> > >
> > > Since the hardware is connected to APIC pin0, it is a BIOS bug
> > > that an ACPI interrupt source override from pin2 to IRQ0 exists.
> > >
> > > With this simple 2.6.5 patch you can specify "acpi_skip_timer_override"
> > > to ignore that bogus BIOS directive. The result is with your
> > > ACPI-enabled APIC-enabled kernel, you'll get IRQ0 IO-APIC-edge timer.
> > >
> > > Probably there is a more clever way to trigger this workaround
> > > automatcially instead of via boot parameter.
>
> > Hi Len, I have updated my nforce2 patches for 2.6.5 to work with your patch.
> > I have tested them only on one nforce2 board Epox 8Rga+ but as little has
> > changed in core functionality from past releases I think all will be OK....
> > Hopefully no clock skew. I saw none on my system but thats no guarantee.
>
> While I don't want to get into the business of maintaining
> a dmi_scan entry for every system with this issue, I think
> it might be a good idea to add a couple of example entries
> for high volume systems for which there is no BIOS fix available.
>
> Got any opinions on which system to use as the example?
> I'll need the output from dmidecode for them.

I have an A7N8X Deluxe v2 BIOS v1007 that I can give u whatever numbers
u need. IOAPIC and APIC are on.

Its running gentoo-dev-sources 2.6.3-r1 plus the idlec1halt patch and
nmi patch from Ross. I guess the kernel doesnt matter too much if its
just board details.

More details of my 2.6.1 days are at
http://atlas.et.tudelft.nl/verwei90/nforce2/

Craig


> > I tried your above patch with the timer_ack on as is default in 2.6.5 and
> > nmi_watchdog=1 failed as expected. I still think Maciej's 8259 ack patch
> > is more complete solution to the ack issue but this one gets watchdog going for
> > nforce2. I cannot see anyone using your above patch without an integrated
> > apic and tsc so I cannot see a problem triggering it off your kern arg.
>
> "acpi_skip_timer_override" is specific to IOAPIC mode,
> since that is the only place that the bogus interrupt
> source override is used.
>
> I'm not clued-in on the nmi_watchdog and 8259 ack issues.
> My focus is primarily the ACPI issues involved in getting
> these systems up and running in IOAPIC mode.
>
> > The second patch is the C1halt update I suggested in another posting.
> > http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-04/1707.html
>
> Clearly this hang issue is more important than the timer issue.
> I'm impressed that you built such a sophisticated patch without
> any support from the vendors. But it would be a "really good thing"
> if we got some input from the vendors before considering putting
> a workaround into the upstream kernel -- for they may have
> guidance which would either simplify it, or make it unnecessary.
> Perhaps Allen Martin at nVidia can comment?
>
> -Len
>
>
>

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