howto: tinkering with spectral scan

[Adrian Chadd]

Hi,

Here's the 30 second rundown for spectral scan:

* update to -HEAD;
* "make" and "make install" in src/tools/tools/ath/; (so you get athspectral)
* checkout svn://svn.freebsd.org/base/user/adrian/ath_radar_stuff;
* install SDL and the SDL TTF font ports;
* "make" in ath_radar_stuff/lib;
* "make" in ath_radar_stuff/src/fft_eval.

Now to use tinker with spectral scan parameters:

* athspectral get - lists parameters
* athspectral start - start a spectral scan
* athspectral enable_at_reset 1|0 - enable or disable spectral scan at
reset (eg during a channel change for a scan operation);

To enable receiving spectral scan PHY errors:

* sysctl dev.ath.X.monpass=0xff - by default PHY errors aren't passed
up via BPF, this (overkill!) enables that;

* ./fft_eval ar9280 if wlanX

  + cursor left/right scrolls;
  + home jumps to 2ghz;
  + end jumps to 5ghz;

On AR9280, if you set ss_count=128, it will just keep generating results;
On AR9285 and AR9287, I think ss_count=0 will keep generating results;
Don't clear ss_short_rpt - it will generate corrupted FFT frames and
there's no way to correct for them (which I'm not yet correcting for
right now - but at least with one FFT report per PHY error I'm able
to);

For extra fun:

* athspectral enable_at_reset 1
* ifconfig wlan0 create wlandev ath0 ssid 'foo123' up
* sysctl dev.ath.0.monpass=0xff
* fft_eval ar9280 if wlan0

.. and scroll around. :-)

I'd love to see screenshots of various kinds of interference seen by
everyone here. :)




Adrian