I have an Dell Latitude XT2 using an Intel WLAN card (lspci lists it as "Intel Corporation Ultimate N WiFi Link 5300") running Lubuntu 12.04 with recent updates. The laptop has a hardware WLAN switch.
I have problems activating the WLAN when booting with the hardware switch set to "off". The situation is a bit confusing, unfortunately.
rfkill lists two WLAN devices (though lspci only shows the Intel one). This is the situation when booting with the hardware switch set to "Off":
0: dell-wifi: Wireless LAN
Soft blocked: yes
Hard blocked: yes
1: dell-bluetooth: Bluetooth
Soft blocked: yes
Hard blocked: yes
2: phy0: Wireless LAN
Soft blocked: yes
Hard blocked: yes
From some tests, I conclude WLAN is only activated when both, the dell-wifi and phy0, are unblocked by soft- and hardware. But I can only unblock dell-wifi after the hardware switch is set to "on".
Procedure right from boot with hardware switch set to "Off":
Soft-unblocking phy0 works as expected. Could be done by start-up script.
sudo rfkill unblock 0: nothing happens. Soft block of dell-wifi not removed.
Set the hardware switch to "on": phy0 gets its hard block removed. Still no WLAN.
sudo rfkill unblock 0: both the soft and hard lock of dell-wifi are removed. WLAN is now active and works.
sudo rfkill block 0: only adds the soft block as expected. WLAN goes off again.
So, in order to activate WLAN, I have to use the hardware switch and afterwards (manually) run a script - that's a bit inconvenient.
Does someone know a better solution? Maybe a daemon could help that listens to rfkill events to unblock dell-wifi after I have set the hardware switch to "on"? (sounds like another workaround)
When booting with the hardware switch set to "On", nothing is blocked neither hard nor soft.