iwlwifi dmar errors in 3.9.2

iwlwifi dmar errors in 3.9.2

[Ilia Mirkin]

Hello,

I recently upgraded to 3.9.2 from 3.7.10, and have begun to see some
DMAR errors in my log. Here are a bunch of them:
http://pastebin.com/wgq0JW0S

This does not seem to negatively affect wifi -- it seems to work just
fine without any extra cajoling, but thought this might be worth
reporting. I also don't know exactly what's triggering the issue.
Hopefully the logs provide the necessary info though.

# lspci -nn -s 03:00.0
03:00.0 Network controller [0280]: Intel Corporation Centrino
Ultimate-N 6300 [8086:4238] (rev 3e)

The machine is a Thinkpad T420s. I've only recently enabled VT-d (and
thus IOMMU), which is perhaps why these didn't happen before... not
sure of the exact timing vs the kernel upgrade.

Let me know if there's any additional info you'd like to get from me.

Thanks,

  -ilia

Re: iwlwifi dmar errors in 3.9.2

[Johannes Berg]

On Mon, 2013-05-20 at 17:12 -0400, Ilia Mirkin wrote:
> Hello,
> 
> I recently upgraded to 3.9.2 from 3.7.10, and have begun to see some
> DMAR errors in my log. Here are a bunch of them:
> http://pastebin.com/wgq0JW0S

Was there anything in the log _before_ this? Like the device already
getting an error, or so?

johannes

Re: iwlwifi dmar errors in 3.9.2

[Ilia Mirkin]

On Tue, May 28, 2013 at 7:43 AM, Johannes Berg
<johannes@sipsolutions.net> wrote:
> On Mon, 2013-05-20 at 17:12 -0400, Ilia Mirkin wrote:
>> Hello,
>>
>> I recently upgraded to 3.9.2 from 3.7.10, and have begun to see some
>> DMAR errors in my log. Here are a bunch of them:
>> http://pastebin.com/wgq0JW0S
>
> Was there anything in the log _before_ this? Like the device already
> getting an error, or so?

Nothing that I felt was relevant, but you be the judge:
http://pastebin.com/s3rV3UK9

  -ilia

Re: iwlwifi dmar errors in 3.9.2

[Johannes Berg]

On Tue, 2013-05-28 at 09:59 -0400, Ilia Mirkin wrote:
> On Tue, May 28, 2013 at 7:43 AM, Johannes Berg
> <johannes@sipsolutions.net> wrote:
> > On Mon, 2013-05-20 at 17:12 -0400, Ilia Mirkin wrote:
> >> Hello,
> >>
> >> I recently upgraded to 3.9.2 from 3.7.10, and have begun to see some
> >> DMAR errors in my log. Here are a bunch of them:
> >> http://pastebin.com/wgq0JW0S
> >
> > Was there anything in the log _before_ this? Like the device already
> > getting an error, or so?
> 
> Nothing that I felt was relevant, but you be the judge:
> http://pastebin.com/s3rV3UK9

Indeed, nothing that seems relevant, particularly no device error or so.
That seems almost like this _causes_ the device error ... hmm. I feel
this is going to be a tricky bug, probably should buy a laptop with
DMAR ... :)

johannes