test on latest hostapd with acs

Michal Kazior michal.kazior
Fri Sep 20 04:30:35 PDT 2013

On 18 September 2013 17:17, Sarah Rumpel <Sarah.Rumpel at barco.com> wrote:
> I figured out that I always have this issue with the large numbers on the channel in use. I can prove this and my results by using iw dev wlan0 survey dump. So it seems like these results of acs are correct, but the driver does not reset the survey data.
> The version I made the tests with is 3.0. I did an update to the latest version (v3.10.4), but there I have the same issues.
> I tried, what you suggested (with modprobe) with the old version of the ath9k driver.
> If I start hostapd too fast after the driver reload, I get one of the two following error message after the last survey. Also hostapd does always, if one of these errors occur, 7 instead of 5 surveys. It jumps to survey 2 again after survey 3.
> the errors are either:
> ACS: Trying survey-based ACS
> ACS: Survey is missing noise floor
> ACS: Channel 7 has insufficient survey data
> ACS: Surveys have insufficient data
> ACS: All study options have failed
> ACS: Failed to start

Apparently ath9k doesn't guarantee it'll fill in noise floor right
away. It's either: try and fix ath9k (assuming doable in a sane way)
or make ACS more resilient to partial/missing survey data.


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