How to make Wavlink USB wifi adapter work again in Ubuntu 18.04.2 LTS after kernel upgrade

Question

Since last kernel update, Wifi adapter stopped working.

Wifi USB adapter: Wavlink AC1300 Dual Band USB Adapter
Model # WL-WN688U8 (Rev.A)

I am using the proposed additional open-source driver:

Linux Kernel version and Ubuntu version:

~$ uname -a  
Linux PC 5.0.0-23-generic #24~18.04.1-Ubuntu SMP Mon Jul 29 16:12:28 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

USB Wifi adapter is recognized as RTL8812AU:

~$ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
(...)
Bus 001 Device 007: ID 0bda:8812 Realtek Semiconductor Corp. RTL8812AU 802.11a/b/g/n/ac WLAN Adapter
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Albeit, there is no wireless interface:

~$ lshw -C network
WARNING: you should run this program as super-user.
  *-network                 
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: enp3s0
       version: 0c
       serial: 1c:1b:0d:df:16:70
       size: 10Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 duplex=half firmware=rtl8168g-2_0.0.1 02/06/13 latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       resources: irq:16 ioport:d000(size=256) memory:f7c00000-f7c00fff memory:f0000000-f0003fff
WARNING: output may be incomplete or inaccurate, you should run this program as super-user.

Seems like dkms module is not installed:

~$ dkms status
rtl8812au, 4.3.8.12175.20140902+dfsg: added

Trying to reinstall:

~$ sudo dkms build -m rtl8812au -v 4.3.8.12175.20140902+dfsg
[sudo] password for user:  

Kernel preparation unnecessary for this kernel.  Skipping...

Building module:
cleaning build area...
'make' all......(bad exit status: 2)
ERROR: Cannot create report: [Errno 17] File exists: '/var/crash/rtl8812au-dkms.0.crash'
Error! Bad return status for module build on kernel: 5.0.0-23-generic (x86_64)
Consult /var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/make.log for more information.

Error output in make.log:

/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/os_intfs.c:779:22: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
  .ndo_select_queue = rtw_select_queue,
                      ^~~~~~~~~~~~~~~~
/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/os_intfs.c:779:22: note: (near initialization for ‘rtw_netdev_ops.ndo_select_queue’)
cc1: some warnings being treated as errors
scripts/Makefile.build:284: recipe for target '/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/os_intfs.o' failed
make[2]: *** [/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/os_intfs.o] Error 1
Makefile:1606: recipe for target '_module_/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build' failed
make[1]: *** [_module_/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-5.0.0-23-generic'
Makefile:1457: recipe for target 'modules' failed
make: *** [modules] Error 2

Any help welcome!

Answer 1

Wifi adapter works again. Here's how to make it work again.

Problem: Driver version 4.3.8.12175 for RTL8812au chipset was not compatible with kernel 5.0.0-23.

Solution: Search for newer driver version for RTL8812au and install.

How To: Download and install gordboy's RTL8812au-5.6.4.1 driver on GitHub and follow readme file for installation : https://github.com/gordboy/rtl8812au-5.6.4.1

Installation with dkms: In short, open terminal (CTRL+ALT+T) and use the following commands in terminal:

sudo apt install git build-essential dkms
sudo git clone https://github.com/gordboy/rtl8812au-5.6.4.1.git 
sudo cp -r rtl8812au-5.6.4.1 /usr/src/rtl8812au-5.6.4.1
sudo dkms add -m rtl8812au -v 5.6.4.1
sudo dkms build -m rtl8812au -v 5.6.4.1
sudo dkms install -m rtl8812au -v 5.6.4.1
sudo dkms status

Output for dkms status should be:

rtl8812au, 5.6.4.1, 5.0.0-23-generic, x86_64: installed

And Wifi adapter should work until next unsupported kernel version upgrade.

To uninstall and remove: Use the following command in terminal:

sudo dkms remove -m rtl8812au -v 5.6.4.1 --all

---

01/06/2021 Edit: Installation of gordboy RTL8812au driver: v.5.9.3.2 (for Linux kernel 5.4) from GitHub.

sudo apt install git build-essential dkms
sudo git clone https://github.com/gordboy/rtl8812au-5.9.3.2.git 
sudo cp -r rtl8812au-5.9.3.2 /usr/src/rtl8812au-5.9.3.2
sudo dkms add -m rtl8812au -v 5.9.3.2
sudo dkms build -m rtl8812au -v 5.9.3.2
sudo dkms install -m rtl8812au -v 5.9.3.2
sudo dkms status

To uninstall and remove this version:

sudo dkms remove -m rtl8812au -v 5.9.3.2 --all

Answer 2

Update: the GitHub repository was updated to 5.6.4.2

sudo apt install git build-essential dkms
sudo git clone https://github.com/gordboy/rtl8812au-5.6.4.2.git 
sudo cp -r rtl8812au-5.6.4.2 /usr/src/rtl8812au-5.6.4.2
sudo dkms add -m rtl8812au -v 5.6.4.2
sudo dkms build -m rtl8812au -v 5.6.4.2
sudo dkms install -m rtl8812au -v 5.6.4.2
sudo dkms status