After a lot of git-bisecting and other testing, it appears that commit
382a103b2b528a3085cde4ac56fc69d92a828b72 is the culprit.
To reproduce the problem, use backports-20130607, and the ath9k defconfig
(with no change otherwise).
The station is unable to authenticate with WPA2 to the AP. Interestingly
enough, if a monitor vif is created and upped beforehand, the authentication
After reverting the commit, authentication succeeds very quickly (without the
need to up a monitor vif), just as expected.
Note that I have kernel 3.8.0 (as per Ubuntu 13.04) and that original
ath9k_htc driver works as expected. This has been also tested on Debian with
driver from original kernel 3.9 (i.e. without backports).
For the moment I can live with the commit reverted, but I suppose it's been
there to fix something else, so this should probably be looked into by someone
more knowledgeable than me.
A person is shit's way of making more shit.
-- S. Barnett, anthropologist.