Re: [RFC][PATCH 0/2] boot interrupts on Intel X58 and 55x0

[Stefan Assmann <sassmann@redhat.com>]

On 07.09.2009 03:33, Henrique de Moraes Holschuh wrote:
> On Fri, 04 Sep 2009, Stefan Assmann wrote:
>> is more serious namely the onboard NIC (8086:10c9) is malfunctioning on some
>> of our test system if the second patch is applied. It fails to acquire an IP
>> from DHCP and we're pretty clueless on this issue right now.
>> Help is greatly appreciated!
> 
> Did you read Intel documet 320839-009, August/2009, already?  It is at:
> http://www.intel.com/Assets/PDF/specupdate/320839.pdf
> 
> I see some stuff there that might be a problem, many of the "issues" are
> related to interrupt handling.  Errata 40 (EOI to IOAPIC can be blocked)
> even states that one should avoid the X58 IOH IOAPIC on stepping B2
> completely, and use the IOAPIC in the ICH10R instead.

Hi Henrique,

good catch, I missed the errata. After reading the details of errata 40
I assume that it's not directly related because the onboard NIC is
connected to the IOH IO-APIC in the first place. No interaction with
another IO-APIC should be involved. The second reason why it's most
likely unrelated is that it only happens when booted with pci=nomsi
(should have mentioned that earlier, sorry) and the errata states:
"The End of Interrupt (EOI) message targeted to the I/OxAPIC will be
blocked in the case that an INTx from a PCIe device and an MSI are
pending inside the Intel X58 Express Chipset."

I've also looked through the other errata and while some of them look
pretty wild I couldn't find anything that might be the root cause for
the observed problem. Same goes for the 55x0 August/2009 spec update.
http://www.intel.com/Assets/PDF/specupdate/321329.pdf

  Stefan
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