Ubuntu – Atheros AR9485 wifi disconnects randomly


I recently bought a new computer that has an Atheros AR9485 wireless NIC. So far it has been working ok except this one issue: Randomly (as far as I can tell) it will completely lose the internet connection. The indicator in the top panel will still say we are connected but the machine has no internet connectivity whatsoever.

I've been able to get it working again by simply disconnecting from my wireless AP and then reconnecting, but this is annoying. Is there anything I can do to make the connection more stable?

I have tried passing the nohwcrypt=1 to the driver, but that made it impossible to connect to any AP, it just infinity attempted to connect.

sudo modprobe -rfv ath9k
sudo modprobe -v ath9k nohwcrypt=1

I've also tried upgrading my kernel to Linux 4.0 but the problem persists.

Exact chip:

02:00.0 Network controller [0280]: Qualcomm Atheros AR9485 Wireless Network Adapter [168c:0032] (rev 01)  


$ ls /sys/class/net/wlan0/device/driver/module/drivers
pci:ath9k  platform:ath9k  

and lsmod:

user@host:~$ lsmod | grep -e ath -e ndis
ath3k                  20480  0 
bluetooth             491520  9 bnep,ath3k,btusb
ath9k                 147456  0 
ath9k_common           32768  1 ath9k
ath9k_hw              458752  2 ath9k_common,ath9k
ath                    32768  3 ath9k_common,ath9k,ath9k_hw
mac80211              724992  1 ath9k
cfg80211              540672  4 ath,ath9k_common,ath9k,mac80211 

output from wireless script: http://paste.ubuntu.com/12625978/

I'm running Ubuntu 15.04 on Linux 4.0.0-040000-generic on a Lenovo G510.

I'm wondering now if I could possibly have anything to do with my wireless mouse, which also operates on 2.4GHz..

Best Answer

I have a Lenovo with a AR9485 but I don't have any close neighbors with wifi and your channel and regulatory settings are the only issues I saw. I know chili555 would suggest using 20Mhz instead of 40 if you have that option on the wireless router

Here is one of his posts copied:

First, check the settings in the router. WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly not TKIP. Second, if your router is capable of N speeds, I have better luck with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz. I also have better luck with a fixed channel, either 1, 6 or 11, rather than automatic channel selection. After making these changes, reboot the router.

Next, I recommend that your regulatory domain be set explicitly. Check yours:

sudo iw reg get 

If you get 00, that is a one-size-maybe-fits-all setting. Find yours here Then set it temporarily:

sudo iw reg set IS  

Of course, substitute your country code if not Iceland. Set it permanently:

gksudo gedit /etc/default/crda

Use nano or kate or vim if you don't have the text editor gedit.

Change the last line to read:


Proofread carefully, save and close the text editor.

Next, I'd set IPv6 to Ignore in Network Manager

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