Friday, March 11, 2011

More wireless hackery

I've had a busy week in the land of FreeBSD wireless driver hacking.

I've been porting over the AR9280 TX calibration changes from ath9k. The AR9280 NIC in my laptop loves it - but the AR9220 based SR71-12 is still unhappy. I'll go poke around and see if I can figure out what the problem is. I have some other AR9280 series NICs to try out.

I've been using hostap mode on the AR5416 and AR9160 and it still seems quite fine and stable.

I've ported over a number of changes to the AR9285 codebase from Linux ath9k. These include:
  • Fixing the TX power calibration curve code;
  • Handling a TX power offset at the beginning of the calibration curve;
  • Updating how the board is initially calibrated on reset;
  • Adding PA calibration.
I'm also trying to remove some of the duplicate code in the HAL that has crept up as chipset support was added.

I'm waiting to hear back from some other users about what effects it has on their setup. I still have to port over the (completely rewritten) radio board configuration code from ath9k that sets up all kinds of radio related gain, offset and various things. There's also software antenna diversity to port over. I hope that this all fixes the issues users have been reporting with AR9285 NICs just plain not working in a lot of instances - but working fine in others. I also hope it fixes the AR2427 support.

I'm still very unclear what may be up with the AR9280 support. The Ubiquiti high-powered cards tend to have strange EEPROM calibration settings, so it's quite possible FreeBSD just handles one of the options badly. That's going to take some time to figure out.

There's no point in getting 802.11n support enabled if I can't TX and RX cleanly, so I'm leaving 802.11n alone (for the most part) until the radios and MACs are behaving themselves.


  1. Hi, I'm really glad that some people is working on the ar9280 solution. I measured a abnormal tx power that higher than the beacon power in 5G. But I think it sould not appear since it has been calibrated. I don't know if the tx power offset or the calibration curve will affect it or not. Is it possible for me to avoid this by porting some codes from ath9k?

  2. .. which card(s) ? Have you tried -HEAD? HEAD should behave much better on the AR9280 now.

  3. I've seen your update for -HEAD, do you have any patch for this update? BTW, have you modified the abnormal tx power that over the beacon power?