Updated driver for RTL88x2bu wifi adaptors based on Realtek's source distributed with myriad adapters.
Realtek's 5.6.1.6 source was found bundled with the Cudy WU1200 AC1200 High Gain USB Wi-Fi Adapter and can be downloaded from Cudy's website.
Build confirmed on:
Linux version 5.4.0-4-amd64 (debian-kernel@lists.debian.org) (gcc version 9.2.1 20200203 (Debian 9.2.1-28)) #1 SMP Debian 5.4.19-1 (2020-02-13)
In order to make direct use of the driver it should suffice to build the driver with make and to load it with insmod 88x2bu.ko. This will allow you to use the driver directly without changing your system persistently.
It might happen that your system freezes instantaneously. Ensure to not loose important work by saving and such beforehand.
If you want to have the driver available at startup, it will be convenient to register it in DKMS. An executable explanation of how to do so can be found in the script deploy.sh. Since registering a kernel module in DKMS is a major intervention, only execute it if you understand what the script does.
Some users reported problems due to Unknown symbol in module. This can be caused by old deployments of the driver still being present in the systems directories.
One solution reported was to forcefully remove all old driver modules:
sudo dkms remove rtl88x2bu/5.8.7.4 --all
find /lib/modules -name cfg80211.ko -ls
sudo rm -f /lib/modules/*/updates/net/wireless/cfg80211.ko
This can also be caused by cfg80211 module not being present in the kernel. You can remedy this by running:
sudo modprobe cfg80211
Starting from Linux 5.18, some distributions have added experimental RTW88 USB support (include RTW88x2BU support). It is not yet stable but if it works well on your system, then you no longer need this driver. But if it doesn't work or is unstable, you need to manually blacklist it because it has a higher loading priority than this external drivers.
Check the currently loaded module using lsmod. If you see rtw88_core,
rtw88_usb, or any name beginning with rtw88_ then you are using the RTW88
driver. If you see 88x2bu then you are using this RTW88x2BU driver.
To blacklist RTW88 8822bu USB driver, run the following command:
echo "blacklist rtw88_8822bu" > /etc/modprobe.d/rtw8822bu.conf
And reboot your system.
Secure Boot will prevent the module from loading as it isn't signed.
Check your secure boot setting with mokutil --sb-state. You should see something like:
SecureBoot disabled
If not, disable secure boot in BIOS.