Re: iwn(4) hangs after r257133

And for reference, here's the paper:

http://hal.inria.fr/docs/00/07/07/84/PDF/RR-5208.pdf



-adrian


On 10 November 2013 10:48, Adrian Chadd <adrian_at_freebsd.org> wrote:
> Right near the end there you have 'status 83' which means 'transmit
> failed, long retry hit' (the status codes are in if_iwnreg.h
> somewhere.) The retry count hit 16, which is the max set for the
> frame.
>
> rate=80 (hex) is MCS0. So, you're seeing retransmits and failures at
> MCS0, which is a bad sign.
>
> But, notice how AMRR increased it to MCS2 at a couple stages, and that
> _always_ fails. But AMRR waits for 10 frame transmits before it
> adjusts the rate up or down.
>
> So yes, we do need to enable MRR again on iwn for things to behave
> better. There are other issues when you start doing larger amounts of
> traffic but I'll cover those later.what?
>
> If someone wants to take a crack at correctly implementing the link
> quality table stuff again then please let me know. As I said before,
> the link quality table setup code is mostly sane. The problem is
> actually correctly setting 'linkq' to start at the selected rate, as
> linkq is an index into that table, not the initial rate.
>
> Thanks!
>
>
>
> -adrian
>
>
> On 10 November 2013 08:33, Stefan Farfeleder <stefanf_at_freebsd.org> wrote:
>> On Sun, Nov 10, 2013 at 05:14:58AM -0800, Adrian Chadd wrote:
>>> yup, same info as brandon. :)
>>
>> http://pastebin.com/MwfL06z7
>>
>> Stefan
>>
>>> On 10 November 2013 04:17, Stefan Farfeleder <stefanf_at_freebsd.org> wrote:
>>> > On Sat, Nov 09, 2013 at 08:29:30PM -0600, Brandon Gooch wrote:
>>> >> Turns out that not enabling MRR causes my Intel Ultimate N WiFi Link
>>> >> 5300 to hang after only a few moments of use.
>>> >>
>>> >> For now, I've just reverted only those aspects of r257133, enabling
>>> >> MRR and keeping the rate index lookup, which seems to do something on
>>> >> my hardware at least (I assume it's not the right thing based on
>>> >> Adrian's analysis, but it works never-the-less).
>>> >>
>>> >> Has anyone else hit this with Intel WiFi hardware?
>>> >>
>>> >> Also, what needs to be done to have MRR working properly?
>>> >
>>> > Hi,
>>> >
>>> > I have problems with iwn (Intel WiFi Link 5100) as well.
>>> >
>>> > Unlike my previous problems, it associates properly and works fine, at
>>> > first. But then, after some minutes, the link quality somehow
>>> > deteriorates and I see serious packet drops. Usually it gets back to
>>> > normal some minutes later, but restarting the interface "fixes" the
>>> > problem. I don't think it's a problem with the signal itself, because
>>> > other devices next to the notebook work just fine during that intervals.
>>> >
>>> > Adrian, do you have any ideas, or some data you want from me?
>>> >
>>> > Stefan
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