Visible 0bda:a811 Realtek WiFi adapter and (I believe installed) device driver not connected

Question

lsusb

Bus 001 Device 002: ID 8087:8000 Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 002: ID 18a5:0246 Verbatim, Ltd 
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 004: ID 0a5c:216d Broadcom Corp. 
Bus 002 Device 005: ID 0cf3:7015 Atheros Communications, Inc. TP-Link TL-WN821N v3 / TL-WN822N v2 802.11n [Atheros AR7010+AR9287]
Bus 002 Device 006: ID 0bda:a811 Realtek Semiconductor Corp. 
Bus 002 Device 002: ID 046d:c52b Logitech, Inc. Unifying Receiver
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

The device I'm having trouble with is 006

dkms status

8812au, 4.2.2, 4.13.0-39-generic, x86_64: installed
bcmwl, 6.30.223.271+bdcom, 4.13.0-39-generic, x86_64: installed
bcmwl, 6.30.223.271+bdcom, 4.4.0-122-generic, x86_64: installed

usb-devices

...

Bus=02 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#=  6 Spd=480 MxCh= 0
D:  Ver= 2.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0bda ProdID=a811 Rev=02.00
S:  Manufacturer=Realtek 
S:  Product=802.11ac WLAN Adapter 
S:  SerialNumber=00e04c000001
C:  #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 6 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)

...

sudo lshw -class network

*-network               
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: enp2s0
       version: 0c
       serial: 00:71:c2:08:aa:48
       size: 10Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8168g-2_0.0.1 02/06/13 latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       resources: irq:46 ioport:e000(size=256) memory:f7b00000-f7b00fff memory:f0a00000-f0a03fff
  *-network UNCLAIMED
       description: Network controller
       product: BCM43142 802.11b/g/n
       vendor: Broadcom Corporation
       physical id: 0
       bus info: pci@0000:04:00.0
       version: 01
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress cap_list
       configuration: latency=0
       resources: memory:f7a00000-f7a07fff
  *-network
       description: Wireless interface
       physical id: 2
       bus info: usb@2:4
       logical name: wlxa0f3c11c58c4
       serial: a0:f3:c1:1c:58:c4
       capabilities: ethernet physical wireless
       configuration: broadcast=yes driver=ath9k_htc driverversion=4.13.0-39-generic firmware=1.4 ip=172.20.10.5 link=yes multicast=yes wireless=IEEE 802.11

What to do to make adapter use driver?

Or have I got this completely wrong?

Answer 1

I answer for future reference, having found the question myself without answer. There are a couple of problems:

1. I had problems correctly identifying the chipset. It seems that this 0bda:a811 is the realtek chipset rtl8812au; at least for me the rtl8812au driver worked.
2. This chipset does not work for Ubuntu 18.04-1 out-of-the-box. Even the rtl8812au-dkms driver that you can install with apt-get does not work. sudo apt-get install rtl8812au-dkms seems to install version 4.3.8 (you can check with dkms status).
3. There is luckily a new version of the driver which does work, but you need to install it manually. See this answer. I don't fully understand if it's the driver that does not work or just some problem with the module loader.

To summarize with commands that will fix your problem:

git clone https://github.com/abperiasamy/rtl8812AU_8821AU_linux.git
cd rtl8812AU_8821AU_linux
sudo make -f Makefile.dkms install

After that, giving dkms status you should see a line like:

rtl8812au, 4.3.14, 4.15.0-30-generic, x86_64: installed

Reboot and it should work.