I recently bought a TL-WN951N PCI card, it gets detected right and the module being used is ath9k.
When trying to set it to master mode however, it prints:
$ iwconfig int1 mode master Error for wireless request "Set Mode" (8B06) : SET failed on device int1 ; Invalid argument.
Linux foo 3.2.0-3-686-pae #1 SMP Mon Jul 23 03:50:34 UTC 2012 i686 GNU/Linux
Anybody knows why?