Re: 3.6.11 AMD-Vi: Completion-Wait loop timed out

Udo van den Heuvel
2013-01-20T11:25:19Z

Hello Jörg,

On 2013-01-20 12:19, Jörg Rödel wrote:
> On Sun, Jan 20, 2013 at 11:40:20AM +0100, Udo van den Heuvel wrote:
>> Hello,
>>
>> On 2013-01-20 11:36, Borislav Petkov wrote:
>>> I know just the guy, CCed. :-)
>>
>> Thanks for the quick response!
>> I found this similar case:
>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1073384
>
> Yes, this is a Hardware issue for which the BIOS does not apply the
> workaround.

Hardware issue? What is wrong c.q. happening?

I have this:

# dmesg|grep IOMMU
[ 0.000000] ACPI: IVRS 000000009dd12420 00070 (v02 AMD AMDIOMMU
00000001 AMD 00000000)
[ 0.000000] Please enable the IOMMU option in the BIOS setup
[ 1.125636] AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40

So kernel says I have no IOMMU but still one is found? (!?)

> The only solution for now is to disable the IOMMU on the
> Trinity based chips.

In PC-BIOS I assume?
I did not yet find an option, but this is the first occurrence.
Can the BIOS vendor fix this? If so: please explain so I cna contact
Gigabyte (motherboard manufacturer)

> The question is what to do now, I tend to disable the IOMMU if a
> Trinity chip is detected. This is not the first report of this problem
> I encountered.

I know, see the URL I posted.
What is the impact of disabling the IOMMU?

Udo