Comment 6 for bug 771758

I am using HP 520 and facing the same problem. I tried setting the itnerface manually up by sudo ifconfig wlan0 up. This turned wifi ON and the wifi switch turned blue as it usually does! but still network manager was showing "wifi disabled by hardware switch". I tried wifi radar (available in package manager) and I was able to see available wifi networks in range. I selected one and got connected. It shows that wifi drivers are installed and working properly but the wifi switch is not turing wifi up! I tried to turn wifi off by pressing the switch and it turned off!
so there is some bug within the network-manager application and the wifi hardware switch!

I also checked from "rfkill list" when I press the wifi switch once, it shows me

0: phy0: Wireless LAN
 Soft blocked: no
 Hard blocked: yes
1: hp-wifi: Wireless LAN
 Soft blocked: no
 Hard blocked: yes
When I press the switch again, it show following:

0: phy0: Wireless LAN
 Soft blocked: no
 Hard blocked: yes
1: hp-wifi: Wireless LAN
 Soft blocked: no
 Hard blocked: no

Please let me know if any more information is required on it!