Wi-fi periodically drops on ubuntu 14.04 LTS

[tgurbanov]

Hi,
Wi-fi connection on my laptop became unstable after I've updated to ubuntu 14.04. Wi-fi periodically drops and it looks like wi-fi is going to sleep. I looked through several solutions (like disabling n-protocol, ignoring IPv6, etc.), but nothing worked for me. In ubuntu 12.04 connection was stable. Here is the output of wifi script: http://pastebin.ubuntu.com/7530945/. Can anybody help me?

$ lspci | grep Wireless
25:00.0 Network controller: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) (rev 01)

[praseodym]

Hi,

N-protocol is not necessary for Atheros chips, disable the hardware encryption and the power management instead:

echo "options ath9k nohwcrypt=1" | sudo tee -a /etc/modprobe.d/ath9k.conf
sudo modprobe -rfv ath9k
sudo modprobe -v ath9k
sudo iwconfig wlan0 power off

Check

grep 11n /etc/modprobe.d/*

for "wrong" configs. How did you disable it?

[tgurbanov]

for "wrong" configs. How did you disable it?

I added

options iwlwifi 11n_disable=1

to /etc/modprobe.d/iwlwifi.conf

echo "options iwlwifi 11n_disable=1" | sudo tee /etc/modprobe.d/iwlwifi.conf
sudo modprobe -rfv iwldvm
sudo modprobe -rfv iwlwifi
sudo modprobe -v iwlwifi

[tgurbanov]

I disabled the hardware encryption run modprobe.

echo "options ath9k nohwcrypt=1" | sudo tee -a /etc/modprobe.d/ath9k.conf
sudo modprobe -rfv ath9k
sudo modprobe -v ath9k

After these actions wi-fi turned off and I couldn't run it. So, I restarted ubuntu. Now wireless connection works.

I tried to run

sudo iwconfig wlan0 power off

, but i got:

$ sudo iwconfig wlan0 power off
Error for wireless request "Set Power Management" (8B2C) :
    SET failed on device wlan0 ; Operation not supported.

Any suggestions?

[tgurbanov]

Also, after several minutes of work, wi-fi connectio drops again

[praseodym]

SO:

sudo rm /etc/modprobe.d/iwlwifi.conf

Change the encryption mode to pure WPA2-AES (CCMP), check the router manual

[tgurbanov]

I found solution here: http://ubuntuforums.org/showthread.p...8#post12963298
I installed backports and now wi-fi working fine.