Are all Atheros Wifi cards libre?

As far as I know all the Atheros wifi cards series AR9xxx and AR5xxx work just fine. I have a couple (I bought one more and keep it ready for the future..) of AR928X and they work splendidly! Cost 15 dollars for 2 wifi cards. You can find them even for 5 bucks.
cheers!

I have a Thinkpad x201 and switched the built-in Intel wifi chip in
favor of a Qualcomm Atheros AR9285 which works just perfect. I got the
Atheros off Ebay for ~3.50€.

The whole process was a bit of a mess but manageable thanks do Lenovo's
whitelist anti-feature. I wrote it all down, sadly it's only in German
but at least the commands or some automated translation service should
help:
http://vinzv.de/wie-man-den-wlan-chipsatz-in-einem-thinkpad-x201-austauscht/

vinz.

No. It's not quite correct to say all Atheros wifi cards or even all Atheros PCIE or mini PCIE or mini PCIE half height cards are free software friendly as some of these cards do require non-free firmware and won't work or won't work fully in Trisquel- or any other free OS/distribution. There are quite a few cards now that require non-free firmware with Atheros chipsets. All the 802.11ac cards for instance and some older cards which include an 802.11n Atheros chipset (including the most common half height cards mini PCIE cards in most laptops right now).

There has been misinformation presented on these forums (which I've mentioned a few times although may not have corrected in every thread on the subject) and on h-node as well as elsewhere. It can be easy to misinterpret test results and conclude cards are free software friendly when they are not. In the one particular case I'm thinking of numerous people here and elsewhere have wrongly concluded one card were free software friendly. Much more recently (past year or two maybe) a new similar card (but rare) with an Atheros chipset did hit the market which is free software friendly humorously which makes it even more confusing (it has an 802.11n chipset, not 802.11ac).

Even with the 802.11n USB Atheros chipsets which have free drivers/firmware not all the USB adapters with these chips are free software friendly. In fact some don't work on GNU/Linux period. The adapters are not using the standard reference design and the driver/firmwares has been modified under license for distribution with the adapters. The end result is these adapters don't work in GNU/Linux- even on distributions which include non-free components.

As I've said before it's very difficult to make any kind of blanket statement or recommend xyz. Even if you can say XYZ chipset is always free software friendly it might not be the case that a particular adapter will work out of the box. There is something called a device ID for example. If the device ID is not in the driver / kernel then it won't know to initiate the adapter and despite it being free software friendly won't work. I've seen this quite a few times over the years and filed a few bug reports over it. Technically if you spend the time modifying the source code you may be able to re-compile and get such a device working. It's actually probably the simplest thing to do as far as coding goes as its just a one line change, but you'll have to do this repeatedly, or until someone adds it the the mainline kernel anyway.