The only thing that matters is the chipset... which is usually not even
specified on the wrapping. Worse: the manufacturer may change the chipset on
a same model, which may used to work with free or no firmware but not anymore
after the change.
As far as I know, The only reliable way to
That is sad indeed. I bought five of those many years ago and free kernels
perfectly support their AR9271 chipset:
$ lsusb
(...)
Bus 001 Device 002: ID 0cf3:9271 Qualcomm Atheros Communications AR9271
802.11n
(...)
Acquiring a USB adapter that works with free software...
The most trustworthy way is to buy from http://libre.thinkpenguin.com which
guarantees that the sold hardware works with free software. You can also buy
a model that was recently reported to work with free software and hope the
