[ath9k-devel] At high attenuation, tx-rate does not drop low enough?

[Ben Greear <greearb@candelatech.com>]

On 10/04/2012 05:01 PM, Adrian Chadd wrote:
> On 4 October 2012 15:29, Ben Greear <greearb@candelatech.com> wrote:
>> More fun with attenuation and ath9k:
>>
>> It seems that the tx-rates do not properly go to lower speeds,
>> at least in some cases.
>>
>> I enabled lots of attenuation, and it gets into a state where the
>> station drops rates down to around 100Mbps, but the AP side stays with
>> high tx-rate.  From sniffing, it seems that STA starts sending ARPs to AP,
>> and AP responds, but packet is never received on the STA.  I *do* see lots
>> of rx-crc errors on the station.
>>
>> If I force the rate to be MCS-0, then it runs just fine.  I haven't yet
>> tried forcing it to run at higher rates.
>
> Erm. Start with the rate control output (sysfs?) and see what the
> pass/fail rates are per TX rate.

It seems I was using the built-in ath9k rate control logic (or,
at least it was compiled in).

I tried changing to minstrel_ht, and then it works fine at lower
speeds, but max speed is only about 230Mbps, when I was getting 330Mbps
max before.

I'm trying now to get an easy way to flip between the rate control
options to make sure it is reproducible.

Thanks,
Ben


>
>
>
> Adrian
>


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com