I have used my Asus ux31 Ultrabook for over a year and I really enjoy the form factor, especially when I am traveling. I work with a lot of Linux servers and have traditionally used Windows on my client machines and I use a lot of Adobe products but here recently I have been working on converting. As soon as I had the os setup on the laptop I started to enjoy the improved workflow but I did notice that my wireless connection kept “bouncing” so I started investigating and here is what I came up with.
First, I disabled hardward encryption on the wireless nic:
I added “ath9k nohwcrypt=1” line in /etc/modprobe.d/ath9k.conf
Then, I updated the wireless drivers:
uname -r produces kernel version information
uname -a produces all the information for the operating system
Upgrade to all latest software using package manager.
$ cd
$ sudo apt-get install --reinstall linux-headers-$(uname -r) build-essential
Navigate to: http://www.orbit-lab.org/kernel/ and navigate through the structure to find the path to the most up to date version of compat-wireless (for me it was http://www.orbit-lab.org/kernel/compat-wireless-3.0-stable/v3.5/compat-wireless-3.5.4-1.tar.bz2 so I will use this as an example).
$ wget http://www.orbit-lab.org/kernel/compat-wireless-3.0-stable/v3.5/compat-wireless-3.5.4-1.tar.bz2
$ tar jxvf compat-wireless-3.5.4-1.tar.bz2
$ cd compat-wireless*
$ make
$ sudo make install
$ sudo make unload
$ sudo modprobe ath9k
$ sudo reboot
This seems to have taken care of most, if not all, of my issues with this card!
Source: http://tech.danbarrese.com/2012/07/12/xps-8500-atheros-ar9485-wifi-doesnt-work-in-linux-solved/