No wifi Networks found on Ubuntu 20.04.3 LTS

Question

Preface : I had "No wifi adapter found" issue on my pc. I asked No wifi adapter found on Ubuntu 20.04.3 LTS, & the answer chili555 given was working fine.

Today after a restart, I am encountering a new issue. Now, wifi is enabled but it can't find any wifi networks. (though USB-Tethering works). The kernel version is 5.13.0-27-generic

1. Output of iwconfig :

lo        no wireless extensions.
usb0      no wireless extensions.
wlp1s0    IEEE 802.11  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=3 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
docker0   no wireless extensions.

2. sudo lshw -C network :

  *-network                 
       description: Wireless interface
       product: MEDIATEK Corp.
       vendor: MEDIATEK Corp.
       physical id: 0
       bus info: pci@0000:01:00.0
       logical name: wlp1s0
       version: 00
       serial: c8:94:02:c1:7a:7b
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress msi pm bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=mt7921e driverversion=5.13.0-27-generic firmware=____010000-20211014150922 latency=0 link=no multicast=yes wireless=IEEE 802.11
       resources: irq:88 memory:e0300000-e03fffff memory:e0400000-e0403fff memory:e0404000-e0404fff
  *-network
       description: Ethernet interface
       physical id: 1
       bus info: usb@1:2
       logical name: usb0
       serial: 82:75:76:11:9e:70
       capabilities: ethernet physical
       configuration: autonegotiation=off broadcast=yes driver=rndis_host driverversion=5.13.0-27-generic duplex=half firmware=RNDIS device ip=192.168.42.130 link=yes multicast=yes port=twisted pair

3. rfkill list all :

0: hci0: Bluetooth
    Soft blocked: yes
    Hard blocked: no
1: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no

4. sudo iwlist scan:

lo        Interface doesn't support scanning.
usb0      Interface doesn't support scanning.
wlp1s0    No scan results
docker0   Interface doesn't support scanning.

5. lspci -nnk | grep 0280 -A3:

01:00.0 Network controller [0280]: MEDIATEK Corp. Device [14c3:0608]
    Subsystem: MEDIATEK Corp. Device [14c3:0608]
    Kernel driver in use: mt7921e
    Kernel modules: mt7921e

6. sudo dmesg | grep mt7:

[    3.629484] mt7921e 0000:01:00.0: enabling device (0000 -> 0002)
[    3.629700] mt7921e 0000:01:00.0: disabling ASPM  L1
[    3.629746] mt7921e 0000:01:00.0: ASIC revision: 79610010
[    3.712374] mt7921e 0000:01:00.0: HW/SW Version: 0x8a108a10, Build Time: 20211014150838a
[    3.724385] mt7921e 0000:01:00.0: WM Firmware Version: ____010000, Build Time: 20211014150922
[    3.754924] mt7921e 0000:01:00.0: Firmware init done
[    5.326846] mt7921e 0000:01:00.0 wlp1s0: renamed from wlan0

I have also tried sudo apt-get install --reinstall network-manager, sudo systemctl restart network-manager.service, sudo /etc/init.d/network-manager force-reload, Reboot mutiple times. But No luck !!

Answer 1

You are using a relatively new and modern Wi-Fi adapter. As far as I know, this adapter doesn't work with the kernel version lower than 5.14. However, kernel 5.15.7+ is not installable on Ubuntu 20.04 LTS. If we look at kernel 5.14, it's EOL. So unfortunately, you cant use your Wi-Fi adapter with 20.04! You've to perform a fresh install of 21.10 (or upgrade using sudo do-release-upgrade) and follow the steps in my this answer and install kernel 5.16.

I'm using the same Wi-Fi adapter as you.

Answer 2

In terminal do

sudo ifconfig wlp1s0 up
sudo iwconfig wlp1s0 power off
sudo iwconfig wlp1s0 txpower 18

That is what we did in chat to get it running, https://chat.stackexchange.com/rooms/133648/discussion-between-arnob-saha-and-jeremy31

Answer 3

Run the module version sanity check, it will show whether the original module exists within the kernel.

sudo apt install --reinstall bcmwl-kernel-source

Ater checking for original module and if not found it will add the generic one.