Subject: Re: introducing ath(4) and the FreeBSD 802.11 layer
To: Christos Zoulas <christos@zoulas.com>
From: Sam Leffler <sam@errno.com>
List: tech-net
Date: 10/16/2003 08:46:02
On Wednesday 15 October 2003 07:41 pm, Christos Zoulas wrote:
> My linksys cardbus card does hardware resets every second. Is anyone else
> seeing this?

The Atheros driver supports 3 different chips; you need to first identify 
whether you have a 5210, 5211, or 5212-based card.  

I'm guessing you have a 5212.  If so there is an issue that is outstanding 
with the anti noise immunity ANI) support in the HAL. This manifests itself 
by a high PHY error rate.  PHY errors for the 5212 are reported through rx 
descriptors marked with the PHY error bit and a high load can overrun the rx 
descriptor list.  When this happens it appears the reset operation can result 
in a DMA abort and generate a "fatal hardware" interrupt.  The result is a 
hardware reset.

You can check all this by looking at the driver statistics.  There's an ioctl 
to obtain them and if you look in the FreeBSD cvs there's a program in

/usr/src/tools/tools/ath

that you might find useful.

	Sam