Comment 8 for bug 1542564

It might still need firmware, so try

wget http://download.windowsupdate.com/d/msdownload/update/driver/drvs/2014/01/20623393_919a4673931aa789f0b1c3eeafb360b36097894a.cab

sudo cabextract 20623393_919a4673931aa789f0b1c3eeafb360b36097894a.cab -F *.dfu -d /lib/firmware/ar3k

It is two commands, the first goes from wget to 894a.cab

Then shutdown and boot it up