LinuxQuestions.org - [SOLVED] Wireless LAN interface do not work after resume

Well, I managed to resolve the issue after more troubleshooting. First off, there is no need to suspend the ath9k module. There were two other issues instead.

Firstly, the AP I was using used a hidden SSID (non-broadcast), and the wlan0 couldn't re-authenticate upon resume. As the use of hidden SSID is not a very effective security measure, I decided to do away with it. After making the changes at the AP, wlan0 managed to re-authenticate itself with the AP.

After successful re-authentication, the wlan0 interface still could not be used to connect to the Internet. The second issue was that dhcpcd was not running after resume. I am not sure if this is the normal. In any case, to resolve the issue, I added a script in /etc/pm/sleep.d/. The script is simply as follows:

Code:

#!/bin/bash                                                                                  

WLAN0_UP=`/sbin/ifconfig | grep wlan0 | awk '{print $1}'`



case $1 in

    hibernate)

        echo "Hey guy, we are going to suspend to disk!"

        ;;

    suspend)

        echo "Oh, this time we're doing a suspend to RAM. Cool!"

        ;;

    thaw)

        echo "oh, suspend to disk is over, we are resuming..."

        #dhcpcd somehow won't re-assign IP to wlan0 after resume                              

        #thus the need of this fix                                                            

        if [ -n $WLAN_UP ]; then

            dhcpcd wlan0

        fi

        ;;

    resume)

        echo "hey, the suspend to RAM seems to be over..."

        #dhcpcd somehow won't re-assign IP to wlan0 after resume                              

        #thus the need of this fix                                                            

        if [ -n $WLAN_UP ]; then

            dhcpcd wlan0

        fi

        ;;

    *)  echo "somebody is calling me totally wrong."

        ;;

esac

Cheers