[ath9k-devel] Question on keycache size.

[Ben Greear <greearb@candelatech.com>]

On 01/12/2012 12:27 AM, Mohammed Shafi wrote:
> Hi Ben,
>
> On Thu, Jan 12, 2012 at 3:25 AM, Ben Greear<greearb@candelatech.com>  wrote:
>> I have an ath9k AP, running 3.0.8 kernel (with a few tweaks).
>> nohwcrypt is enabled.
>>
>> I set up some other machines with virtual stations, a total of
>> around 450 and had them associate with the AP.
>>
>> It seems to have worked, at least for a while, but then I started
>> seeing loss of station communication, and in the AP logs I see
>> things like this:
>>
>> Jan 11 13:47:03 localhost kernel: ath: keycache entry 228 out of range
>
> may be we should put 'nohwcrypt' check in ath9k_sta_add and
> ath9k_sta_remove before doing ath_key_config&  ath9k_del_ps_key? i
> will try to analyze the code

Ok, I will be happy to test patches..I can easily associate 128+ stations
with an AP and drive traffic.

 From some private email responses, it would appear that packet aggregation
may be part of the problem.  I could associate 400+ stations, and drive low-level
traffic (one pkt every second or so per station).  The problem started when I
created a 100 pkt per second traffic flow (142 byte pkts if that matters).

If it does turn out that 128+ stations requires nohwcrypt, we should
fail the add of the 129th if using hwcrypt so that folks don't have to
debug tricky problems....

Thanks,
Ben


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