RZ608 MT7921K Wireless LAN Driver is not supported on ubuntu 18.04

I Have full amd laptop and and i have RZ608 (MT7921K) and ubuntu does not find the module so the driver is missing. I tried to find a driver and only solution show up was updating kernel to 5.14+. I updated but still had the same issue. Additionally, in MediaTek i only saw upto MT7921 supported by kernel version 5.12+ not MT7921K so where can i find a driver for this module. Any help is appreciated.

The output of lspci -nnk | grep 0280 -A3:

05:00.0 Network controller [0280]: MEDIATEK Corp. Device [14c3:0608]
    Subsystem: MEDIATEK Corp. Device [14c3:0608]
06:00.0 Non-Volatile memory controller [0108]: Kingston Technology Company, Inc. Device [2646:500c] (rev 01)
    Subsystem: Kingston Technology Company, Inc. Device [2646:500c]

The output of:

wget https://gitlab.com/jeremy53561/backports-11-26/-/raw/main/backports-5.15-rc6-1.tar.gz

--2021-11-27 16:56:21--  https://gitlab.com/jeremy53561/backports-11-26/-/raw/main/backports-5.15-rc6-1.tar.gz
Resolving gitlab.com (gitlab.com)... 172.65.251.78, 2606:4700:90:0:f22e:fbec:5bed:a9b9
Connecting to gitlab.com (gitlab.com)|172.65.251.78|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://gitlab.com/users/sign_in [following]
--2021-11-27 16:56:21--  https://gitlab.com/users/sign_in
Reusing existing connection to gitlab.com:443.
HTTP request sent, awaiting response... 503 Service Temporarily Unavailable
2021-11-27 16:56:21 ERROR 503: Service Temporarily Unavailable.

Hey i get the file in the first link from linux server as .xz file and tried to do the:

make defconfig-wifi

result is:

lex -ozconf.lex.c -L zconf.l
make[2]: lex: Command not found
Makefile:23: recipe for target 'zconf.lex.c' failed
make[2]: *** [zconf.lex.c] Error 127
Makefile.real:41: recipe for target 'defconfig-wifi' failed
make[1]: *** [defconfig-wifi] Error 2
Makefile:40: recipe for target 'defconfig-wifi' failed
make: *** [defconfig-wifi] Error 2

In terminal

sudo apt install build-essential flex bison
wget https://gitlab.com/jeremy53561/backports-11-26/-/raw/main/backports-5.15-rc6-1.tar.gz
tar -xvf backports-5.15-rc6-1.tar.gz
cd backports-5.15-rc6-1
make clean
make defconfig-wifi
make
sudo make install
cd /lib/firmware/mediatek
sudo wget https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/plain/mediatek/WIFI_MT7961_patch_mcu_1_2_hdr.bin
sudo wget https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/plain/mediatek/WIFI_RAM_CODE_MT7961_1.bin

Check Secure boot status with mokutil --sb-state as Secure Boot needs to be disabled in UEFI settings for the unsigned module to be loaded

Reboot

Just for the record, Linux kernel's driver module mt7921e does work with this card. I'm on 5.15.2. If you already have this module, you won't need anything other than some configs to workaround this for now.

But, for now it seems that this module currently doesn't include a match for this card's id until this patch hit: https://patchwork.kernel.org/project/linux-wireless/patch/84ab45bf42f57fd0301c156ffc11d0fe330ff1f8.1636857817.git.deren.wu@mediatek.com/

So, currently I'm using a modprobe rule and a udev rule to automatically load the module and use it for the card.

$ cat /etc/modprobe.d/rz608.conf
alias pci:v000014C3d00000608sv*sd*bc*sc*i* mt7921e

$ cat /etc/udev/rules.d/99-rz608.rules
SUBSYSTEM=="drivers", DEVPATH=="/bus/pci/drivers/mt7921e", ATTR{new_id}="14c3 0608"

If you only need it to work for this boot:

# modprobe mt7921e
# echo 14c3 0608 > /sys/bus/pci/drivers/mt7921e/new_id

1. Modalias
2. udev(7)