iwn(4) hangs after r257133
Lars Engels
lars.engels at 0x20.net
Mon Nov 11 15:04:05 UTC 2013
Am 11.11.2013 09:18, schrieb Stefan Farfeleder:
> On Sun, Nov 10, 2013 at 02:01:12PM -0800, Adrian Chadd wrote:
>> Yes. So one of the.. unfortunately broken things in iwn is the ampdu
>> tx
>> code doesn't do retransmits. So if amrr picks a rate that fails to
>> transmit
>> everything, the driver doesn't retransmit them. It frees them.
>>
>> Now when amrr is enabled the hardware will retry at lower rates until
>> something succeeds. But it still doesn't retransmit things. I believe
>> it
>> should be.
>>
>> So yes its more broken with Mrr disabled. But enabling mrr doesn't fix
>> it.
>> It just makes it less broken. Someone needs to implement ampdu
>> retransmit.
>>
>> The latest iwn code in head at least tells the rate selection code
>> that a
>> total ampdu tx failure occured. This BTW is one of the hangs I fixed -
>> if
>> you hit a point where you never successfully transmitted an ampdu at a
>> rate
>> the rate would never be decreased.
>>
>> Now to be clear. I won't be in implementing ampdu retransmit. I'll
>> maybe
>> fix last multi rate retry once the new hardware support is in. I would
>> really appreciate help here with these. Everyone with iwn hardware
>> will
>> appreciate it :)
>
> In the mean time, wouldn't it make sense to disable ampdu tx in iwn
> then? Or to disallow the combination Mrr + ampdu?
Yes, please. I'm also encountering this.
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