Libre kernel & USB wifi
In my x60t I will change the internal wifi card so at the moment I plugged a USB TL-WN722N, and with trisquel 6 fully updated work fine...
if I install libre kernel the wifi try to connect but never able to do it.
The Linux kernels available from Trisquel's repositories all free/libre. I assume you are referring to the latest Linux-libre kernels (version 3.15.x), like those in jxself's repository (see https://trisquel.info/en/wiki/update-linux-libre-kernel for the different options).
The TL-WN722N Wifi adapter has a AR9271 chipset. ath9k_htc drives it. According to Chris, there is a bug with ath9k_htc on Linux 3.15.x (when connecting to encrypted access points): https://trisquel.info/en/forum/penguin-wireless-n-adapters-ath9khtc-bug-atheros-ar9271
Here is the bug: https://bugzilla.kernel.org/show_bug.cgi?id=78581
And here is a temporary fix: https://www.thinkpenguin.com/gnu-linux/penguin-wireless-n-usb-adapter-gnu-linux-tpe-n150usb-tpe-n150usbl-tpe-nusbdb
thx magic banana for the infos, i'll check it and let u know if this solve the issue.