Though the reason has not found yet, the wifi connection on Raspberry Pi becames disabled. After some investigations, I found that it's blocked by rfkill
.
root@raspberrypi:~# rfkill list
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: yes
Hard blocked: no
By executing rfkill unblock all
, wifi started working as before.
root@raspberrypi:~# rfkill unblock all
root@raspberrypi:~# rfkill list
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no