From: Tony Toole (tony_at_valemount.com)
Date: 2002-06-24 15:04:03 UTC
Yes, 2304 is the maximum as described by the 802.11 standard.
This would come to show that the driver may be getting slightly corrupt data at times. I've never really used HostAP except out of curiosity, but I can assure you it is not normal behavior for Prism 2 / 2.5 cards to randomly introduce corrupt packets like they are. Perhaps there is a race, or something similar that is corrupting access to the BAP register during the interrupt. Good luck in solving the problem!
There are some things you can try to help troubleshoot. Find where the
driver sets RID 0xFC07 (cnfMaxDataLen), and move it lower, to 1514 to see if
your problems persist.
In my experience, the Prism2 (as well as all other 802.11 compliant cards) ignore rx frames with data lengths larger than this number. You may need to increase it to ~1522 if you are using the WDS hack, which appends a 6-byte (plus padding) mac address to the end if your data.
Good luck! I'm interested in what you find. While developing our drivers, I've never seen this problem crop up before, using either Prism 2 / 2.5 or ORiNOCO cards..
WebWorld Warehouse Ltd.
> Yes, but this occurs in the prism2_80211_rx function. Is it also the
> maximum size they can receive?
> On Fri, 21 Jun 2002, Tony Toole wrote:
> > That is the maximum data packet size the Prism radios can transmit.
> > MTU of 1500, this size limit should never be reached.
> > Tony Toole
> > WebWorld Warehouse Ltd.
> > http://www.station-server.com/
> > StarOS Software solutions for all your Wireless needs.
> > Download your free trial today!
> > ----- Original Message -----
> > From: "Vincas Ciziunas" <winkie_at_faceprint.com>
> > To: <hostap_at_lists.ssh.com>
> > Sent: Friday, June 21, 2002 1:27 PM
> > Subject: Why is PRISM2_DATA_MAXLEN there?
> > > I was wondering why PRISM2_DATA_MAXLEN is there, and why it's 2304. I
> > > using the hostap driver on several hosts, and was curious to find it
> > > complaining about the size of data being larger than that. There were
> > > some portscans going over the network at the time. What is the
> > > purpose, and what does it limit?
> > >
> > > Vincas
> > >
> > >