Verified with mainline kernel 3.16.0-031600-generic #201408031935, wifi slider works as expected.
rfkill status before and after the slider change:
ubuntu@201404-14986:~$ rfkill list
1: dell-wifi: Wireless LAN
Soft blocked: no
Hard blocked: no
2: dell-bluetooth: Bluetooth
Soft blocked: no
Hard blocked: no
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
4: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
ubuntu@201404-14986:~$ rfkill list
1: dell-wifi: Wireless LAN
Soft blocked: no
Hard blocked: yes
2: dell-bluetooth: Bluetooth
Soft blocked: no
Hard blocked: yes
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: yes
Verified with mainline kernel 3.16.0- 031600- generic #201408031935, wifi slider works as expected.
rfkill status before and after the slider change: 201404- 14986:~ $ rfkill list 201404- 14986:~ $ rfkill list
ubuntu@
1: dell-wifi: Wireless LAN
Soft blocked: no
Hard blocked: no
2: dell-bluetooth: Bluetooth
Soft blocked: no
Hard blocked: no
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
4: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
ubuntu@
1: dell-wifi: Wireless LAN
Soft blocked: no
Hard blocked: yes
2: dell-bluetooth: Bluetooth
Soft blocked: no
Hard blocked: yes
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: yes