Re: DMAR:[fault reason 02] Present bit in context entry is clear(firewire-ohci)

From: Clemens Ladisch
Date: Wed Nov 30 2011 - 11:16:07 EST


TomÃÅ JanouÅek wrote:
> On Sat, May 22, 2010 at 12:09:05PM -0700, Jesse Barnes wrote:
>> On Sat, 22 May 2010 19:40:43 +0100
>> David Woodhouse <dwmw2@xxxxxxxxxxxxx> wrote:
>>> [...]
>>> Yeah, the DMAR looks at the source-id in the PCIe transactions, and it
>>> sounds like those are all 04:00.0. But we've probably set up the DMAR to
>>> allow the transactions from 04:00.4, and then it naturally faults when a
>>> "different" device actually ends up doing the transaction.
>>>
>>> If you make the pci_find_upstream_pcie_bridge() function do the
>>> appropriate thing for this device, does it then work as expected?
>>>
>>> Whether that's a _sane_ thing to do or not is possibly more of a Jesse
>>> question...
>>
>> Well, if cardbus bridges tend to behave this way in general it would
>> make sense to simply use the cardbus bride id everywhere, rather than
>> the specific functions of the device. Cc'ing Dominik.
>
> Any news on this one?

Apparently not.

Try the patch in <https://bugzilla.redhat.com/show_bug.cgi?id=605888>
that is intended to work around the bug in your Ricoh chip. Alternatively,
disable VT-d or FireWire in the BIOS, or add the kernel parameter
"intel_iommu=off".


Regards,
Clemens
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