HOT: An effort is underway to add in-kernel support for the rtl8821/11au chipset. For more information, go to: https://github.com/morrownr/8821au-20210708/issues/133
Note: Please read the file "supported-device-IDs" for information about how to confirm that this is the correct driver for your adapter.
Note: Posting this driver is not a recommendation for Linux users to buy USB WiFi adapters based on the Realtek chipsets supported by this driver. Realtek out-of-kernel wifi drivers, such as this one, are not Linux Wireless Standards compliant and appear to be designed to be used by skilled programmers producing products such as embedded systems. Users of desktop and server distros such as Ubuntu, Debian, Manjaro, Fedora, Raspberry Pi OS and other mainline desktop and server distros will likely find adapters that use in-kernel drivers (Linux Wireless Standards compliant) to be more stable and much more trouble-free. The following links will provide more information:
USB WiFi adapters that are supported with Linux in-kernel drivers
USB WiFi adapter information for Linux
FAQ.md8821au.confNote: Additional CPU architectures may work but I currently only have the hardware to test the above.
Note: Kernels earlier than 5.4 may work but are not tested or supported.
Note: The information in this section depends largely on user reports which can be provided via PR or message in Issues.
Arch Linux (kernels 5.4, 5.11 and 6.6)
Armbian (kernel 5.15) (Rock 4 SE (Rock 4b image with xfce))
Debian (kernels 5.10, 5.15, 6.1 and 6.6)
Fedora Fedora 38 (6.2.13-300)
Manjaro (kernel 5.15)
openSUSE Tumbleweed (rolling) (kernel 5.15)
Raspberry Pi OS (2023-12-05)(ARM 32 bit and 64 bit)
Raspberry Pi Desktop (2022-07-01) (x86 32 bit) (kernel 5.10)
Ubuntu 22.04 (kernel 5.15) and 22.10 (kernel 5.19) (kernel 6.5)
Note: Red Hat Enterprise Linux (RHEL) and distros based on RHEL are supported by Red Hat devs due to the way kernel patches are handled in Red Hat. I support knowledgable RHEL developers if they want to merge the required support and keep it current. I reserve the right to delete this support without notice if it causes any problems.
Current RHEL maintainer: none
Note: Android is supported in the driver according to Realtek. I will support knowledgable Android developers if they want to merge and keep current the required support (most likely just instructions about how to compile and maybe a modification or two to the Makefile).
Current Android maintainer: none
Note: OpenWRT is not supported. OpenWRT provides drivers for USB WiFi adapters. OpenWRT provided drivers include support for the MT7921au (AXE3000), MT7612u (AC1200), MT7610u (AC600) chipsets. It is a challenge to use Realtek based adapters that use out-of-kernel drivers with OpenWRT so it is strongly advised to use the already supported chipsets.
Warning: It is recommended that you follow the installation instructions in the Installation Steps section. Avoid installation by downloading the zip file if at all possible. Support can only be provided, on a best effort basis, if the instructions in the Installation Steps section are followed.
Warning: Installing multiple out-of-kernel drivers for the same hardware
usually does not end well. The install-driver.sh script has the
capability to detect and remove most conflicting drivers but not all. If
this driver does not work well after installation and you have
previously installed a driver that you did not remove, it is suggested
that you run the following command in an effort to determine if you need
to take action to manually remove conflicting drivers:
sudo dkms statusWarning: If you decide to do a distro upgrade, which will likely install a new version of kernel such as 5.15 to 6.1, you need to update this driver with the newest available code and then reinstall it before performing the disto upgrade. Use the following commands in the driver directory:
git pullsudo sh install-driver.shInternet access is required for initial installation. There are numerous ways to enable temporary internet access depending on your hardware and situation. One method is to use tethering from a phone.. Another method is to keep a WiFi adapter that uses an in-kernel driver in your toolkit.
You will need to use the terminal interface. The quick way to open a terminal: Ctrl+Alt+T (hold down on the Ctrl and Alt keys then press the T key).
An alternative terminal is to use SSH (Secure Shell) from the same or from another computer, in which case you will be in a suitable terminal after logging in, but this step requires that an SSH daemon/server has already been configured. (There are lots of SSH guides available, e.g., for the Raspberry Pi and for Ubuntu. Do not forget to secure the SSH server.)
You will need to have sufficient access rights to use sudo so that commands
can be executed as the root user. (If the command sudo echo Yes returns
"Yes", with or without having to enter your password, you do have sufficient
access rights.)
DKMS is used for the installation, if available. DKMS is a system utility which will automatically recompile and reinstall this driver when a new kernel is installed. DKMS is provided by and maintained by Dell.
It is recommended that you do not delete the driver directory after installation as the directory contains information and scripts that you may need in the future.
Secure Boot: see FAQ.
Note: The installation instructions are for the novice user. Experienced users are welcome to alter the installation to meet their needs. Support will be provided, on a best effort basis, based on the steps below. Another way to word this paragraph is that if you do not follow the below steps for installation, you are your own tech support.
Note: If your Linux distro does not fall into one of options listed
below, you will need to research how to update and upgrade your
system packages.
sudo apt update && sudo apt upgradesudo pacman -Syusudo dnf upgradesudo zypper updatesudo xbps-install -SyuNote: It is recommended that you reboot your system at this point. The rest of the installation will appreciate having a fully up-to-date system to work with. The installation can then be continued with Step 3.
sudo rebootNote: If your Linux distro does not fall into one of options listed below, you will need to research how to properly setup up the development environment for your system. General guidance follows.
Development Environment Requirements: (package names may vary by distro)
gcc make bc kernel-headers build-essential gitdkms rfkill iw ipopenssl sign-file mokutilNote: The below options should take care of the mandatory and highly recommended requirements. If Secure Boot is active on your system, please also install the mandatory packages for Secure Boot as shown above.
sudo apt install -y build-essentialsudo apt install -y raspberrypi-kernel-headers build-essential bc dkms gitsudo apt install -y linux-headers-$(uname -r) build-essential bc dkms git libelf-dev rfkill iwsudo apt install -y build-essential dkms git iwNote: Fedora users should also install openssl if secure boot is
active.
sudo dnf -y install git dkms kernel-develsudo zypper install -t pattern devel_kernel dkmssudo apk add linux-lts-dev make gccsudo xbps-install linux-headers dkms git makeIf using pacman
sudo pacman -S --noconfirm linux-headers dkms git bc iwNote: The following is needed if using Manjaro for RasPi4B.
sudo pacman -S --noconfirm linux-rpi4-headers dkms git bcNote: If you are asked to choose a provider, make sure to choose the one that corresponds to your version of the linux kernel (for example, "linux510-headers" for Linux kernel version 5.10). If you install the incorrect version, you'll have to uninstall it and install the correct version.
If using other methods, please follow the instructions provided by those methods.
mkdir -p ~/srccd ~/srcgit clone https://github.com/morrownr/8821au-20210708.gitcd ~/src/8821au-20210708install-driver.sh)Important: The compilation may fail if the major version of gcc that is in use is not the same as the major version of gcc that was used to compile the kernel that is in use:
Example of bad situation:
gcc 12.1 (used to compile the kernel)
gcc 10.3 (version of gcc in use)Example of good situation:
gcc 12.2 (used to compile the kernel)
gcc 12.1 (version of gcc in use)To determine the values:
cat /proc/versiongcc --versionIf you find your system in a bad situation, it is recommended that you install a version of gcc that matches the major version of gcc that was used to compile your kernel. Here is an example for Ubuntu:
sudo apt install gcc-12Note: If your system is a low memory system, it is recommended that you terminate running apps so as to provide the maximum amount of RAM to the compilation process.
Note: For automated builds (non-interactive), use NoPrompt as an
option.
sudo ./install-driver.shor
sudo sh install-driver.shNote: If you elect to skip the reboot at the end of the installation script, the driver may not load immediately and the driver options will not be applied. Rebooting is strongly recommended.
Note: Fedora users that have secure boot turned on may need to run the following to enroll the key:
sudo mokutil --import /var/lib/dkms/mok.pubNote: The installation script, install-driver.sh , automates the
installation process, however, if you want to or need to do a basic
command line installation, use the following:
make cleanmake -j$(nproc)If secure boot is off:
sudo make installsudo rebootIf secure boot is on:
Note: Please read to the end of this section before coming back here to enter commands.
sudo make sign-installNote: You will be promted for a password, please remember the password as it will be used in some of the following steps.
sudo rebootThe MOK managerment screen will appear during boot:
Shim UEFI Key Management
Press any key...
Select "Enroll key"
Select "Continue"
Select "Yes"
When promted, enter the password you entered earlier.
Warning: If you enter the wrong password, your computer will not be bootable. In this case, use the BOOT menu from your BIOS to boot then as follows:
sudo mokutil --resetRestart your computer. Use the BOOT menu from BIOS to boot. In the MOK
managerment screen, select reset MOK list, then reboot and retry from
the above step sudo make sign-install.
Note: If you use the Manual Installation Instructions, you will need to repeat the installation process each time a new kernel is installed in your distro.
To remove the driver if installed by the Manual Installation Instructions:
sudo make uninstallsudo rebootNote: If you use the manual installation instructions, or if dkms is not installed, you will need to repeat the process each time a new kernel is installed in your distro.
edit-options.sh)Note: In Linux, driver options are also called module parameters .
A file called 8821au.conf will be installed in /etc/modprobe.d by
default if you use the installation script, install-driver.sh. If you
are following the Manual Installation Instructions, you can use the
edit-options.sh script to install and/or edit the file.
Note: The installation script, install-driver.sh. will prompt you to
edit the options.
8821au.conf will be read and applied to the driver on each system boot.
To edit the driver options file, run the edit-options.sh script
sudo ./edit-options.shNote: Documentation for Driver Options is included in the file
8821au.conf.
Note: Linux development is continuous therefore work on this driver is continuous.
Note: Upgrading the driver is advised in the following situations:
cd ~/src/8821au-20210708git pullNote: The install-driver.sh script will automatically remove the
previously installed driver.
sudo ./install-driver.shremove-driver.sh)Note: Removing the driver is advised in the following situations:
Note: The following removes everything that has been installed, with the exception of the packages installed in Step 3 and the driver directory. The driver directory can be deleted after running this script.
cd ~/src/8821au-20210708Note: For automated builds (non-interactive), use NoPrompt as an
option.
sudo ./remove-driver.shNote: These recommendations apply when using your adapter in managed (client) mode, not AP mode.
Note: These are general recommendations, some of which may not apply to your specific situation.
Security: Set WPA2-AES or WPA2/WPA3 mixed or WPA3. Do not set WPA2 mixed mode or WPA or TKIP.
Channel width for 2.4 GHz: Set 20 MHz fixed width. Do not use 40 MHz or 20/40 automatic.
Channels for 2.4 GHz: Set channel 1 or 6 or 11 depending on the congestion at your location. Do not set automatic channel selection. As time passes, if you notice poor performance, recheck congestion and set channel appropriately. The environment around you can and does change over time.
Mode for 2.4 GHz: For best performance, set "N only" if you no longer use B or G capable devices.
Network names: Do not set the 2.4 GHz Network and the 5 GHz Network to the same name. Note: Unfortunately many routers come with both networks set to the same name. You need to be able to control which network that is in use so changing the name of one of the networks is recommended. Since many IoT devices use the 2.4 GHz network, it may be better to change the name of the 5 GHz network.
Channels for 5 GHz: Not all devices are capable of using DFS channels (I'm looking at you Roku.) It may be necessary to set a fixed channel in the range of 36 to 48 or 149 to 165 in order for all of your devices to work on 5 GHz. (For US, other countries may vary.)
Best location for the WiFi router/access point: Near center of apartment or house, at least a couple of feet away from walls, in an elevated location. You may have to test to find the best location is in your environment.
Check congestion: There are apps available for smart phones that allow
you to get an idea of the congestion levels on WiFi channels. The apps
generally go by the name of WiFi Analyzer or something similar.
After making and saving changes, reboot the router.
Moving your USB WiFi adapter to a different USB port has been known to fix a variety of problems.
If connecting your USB WiFi adapter to a desktop computer, use the USB ports on the rear of the computer if you encounter any problems. Why? The ports on the rear are directly connected to the motherboard which will reduce problems with interference and disconnection. An extension cable can be helpful to position the adapter for best reception.
If your USB WiFi adapter is USB 3 capable and you want it to operate in USB3 mode, plug it into a USB 3 port.
Avoid USB 3.1 Gen 2 ports if possible as most currently available adapters have been tested with USB 3.1 Gen 1 (aka USB 3) and not with USB 3.1 Gen 2.
If you use an extension cable and your adapter is USB 3 capable, the cable needs to be USB 3 capable (if not, you will be limited to USB 2 speeds).
Extention cables can be problematic. A way to check if the extension cable is the problem is to plug the adapter temporarily into a USB port on the computer.
Some USB WiFi adapters require considerable electrical current and push the capabilities of the power available via USB port. One example is adapters that use the Realtek 8814au chipset. Using a powered multiport USB extension can be a good idea in cases like this.
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