After a recent update of Ubuntu 20.04.1 LTS when I resume my laptop from suspend my WIFI does not work. WIFI does work after rebooting the laptop.
Here is what I have tried.
sudo systemctl restart NetworkManager
sudo service network-manager restart
sudo nmcli networking off
sudo nmcli networking on
Non of these worked. There were no problems before the update and restoring to a previous state with timeshift resolves the problem. Here are the outputs of some commands that my help.
sudo lshw -C network
-network DISABLED
description: Wireless interface
product: Centrino Advanced-N 6235
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:02:00.0
logical name: wlp2s0
version: 24
serial: c4:85:08:43:dc:6c
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=5.8.0-34-generic firmware=18.168.6.1 6000g2b-6.ucode latency=0 link=no multicast=yes wireless=IEEE 802.11
resources: irq:31 memory:f1500000-f1501fff
-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:03:00.0
logical name: enp3s0
version: 06
serial: e8:03:9a:e8:1a:51
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=5.8.0-34-generic firmware=rtl8168e-3_0.0.4 03/27/12 latency=0 link=no multicast=yes port=MII
resources: irq:19 ioport:2000(size=256) memory:f1404000-f1404fff memory:f1400000-f1403fff
nmcli device
DEVICE TYPE STATE CONNECTION
30:D9:D9:28:09:E4 bt disconnected --
enp3s0 ethernet unavailable --
wlp2s0 wifi unavailable --
lo loopback unmanaged --
lspci -knn | grep Net -A3; rfkill list
02:00.0 Network controller [0280]: Intel Corporation Centrino Advanced-N 6235 [8086:088e] (rev 24)
Subsystem: Intel Corporation Centrino Advanced-N 6235 AGN [8086:4060]
Kernel driver in use: iwlwifi
Kernel modules: iwlwifi
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
2: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
rfkill
ID TYPE DEVICE SOFT HARD
0 wlan phy0 unblocked unblocked
2 bluetooth hci0 unblocked unblocked
EDIT: the problem occur with Linux kernel 5.8 but no with Linux kernel 5.4