No wifi Networks found on Ubuntu 20.04.3 LTS

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 !!

3 Answers

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.

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,

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.