ath(4) AR9280 freeze / deadlock ?

[Sébastien Bocahu <lists%zecrazytux.net@localhost>]

Hi,

I run NetBSD 6 RC1 on a soekris router. I recently added a TP-LINK TL-WN861N
wireless board to create an AP. Since then, the whole system randomly freezes or
crash. The router had been running without any problem for months (5.1 then 6
beta and rc) before, so I believe the ath(4) driver causes this issue.

Also, reception quality is very poor.

Some facts:

- Dmesg reports an Atheros AR9280 chip.
- When the freeze happens, nothing shows up in either the logs nor the serial
  console.
- It seems that devices that are connected to the AP keep believing they are 
associated.
- No core dump, ddb doesn't trigger.
- The router has to be hard rebooted.

Has anybody experienced same issues ?
Is there any workaround ?
Is there any plan to update the driver ? 

I read news from the FreeBSD world, and it seems that they had many problems
with these chips, but they have done a lot of work on this driver (N support if
I understand well).
Unfortunately, I could'nt find a single commit with a reference to this kind of
freeze/deadlock.

Regards,

Sebastien