USB wifi adapter module does not work after version update

[Randy Bass]

Pre-18.04, I had to download and install the module for my TP-Link T4U USB WiFi adapter manually. With most (not all) previous updates, the module would be incorporated in the update automatically.

With 18.04, this module is now included in the standard repository, which I appreciate. However, every time I do a version update ( twice, from 4.15.0-44 to 4.15.0-45, and now 4.15.0-45 to 4.15.0-46), the module is no longer operational following the update. I expect the module, now that it is in the standard repository, to be incorporated in the update every time.

After an update, I can issue a command

lshw -c network

and it shows only my onboard wired adapter. If I connect my wired adapter and issue the command

sudo apt install rtl8812au-dkms

I get the response that the current version is already the newest version, and nothing happens. I need to first remove the current module, then reinstall it, and then reboot.

sudo apt remove rtl8812au-dkms
sudo apt install rtl8812au-dkms
reboot

The module is then functional when the system starts up again.

I am currently on:
Description: Ubuntu 18.04.2 LTS
Release: 18.04
Linux 4.15.0-46-generic i686

rtl8812au-dkms:
  Installed: 4.3.8.12175.20140902+dfsg-0ubuntu8
  Candidate: 4.3.8.12175.20140902+dfsg-0ubuntu8
  Version table:
 *** 4.3.8.12175.20140902+dfsg-0ubuntu8 500
        500 http://us.archive.ubuntu.com/ubuntu bionic/universe i386 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: rtl8812au-dkms 4.3.8.12175.20140902+dfsg-0ubuntu8
ProcVersionSignature: Ubuntu 4.15.0-46.49-generic 4.15.18
Uname: Linux 4.15.0-46-generic i686
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: i386
CurrentDesktop: XFCE
Date: Tue Mar 19 11:15:38 2019
InstallationDate: Installed on 2015-09-22 (1273 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta i386 (20150805)
PackageArchitecture: all
SourcePackage: rtl8812au
UpgradeStatus: Upgraded to bionic on 2019-01-17 (61 days ago)

[Oliver Gerlich (ogerlich)]

This might be the same issue as #1705820 . Randy: could you try applying the patch described in https://bugs.launchpad.net/ubuntu/+source/rtl8812au/+bug/1705820/comments/10 and see if that fixes the problem for you?

[Randy Bass (randybass)]

Sorry to take so long to get back to you, @ogerlich. I applied the patch, and yes, did confirm that this fixed the problem on updating to version Linux 5.0.0-31-generic x86_64. Than you so much for your help.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Randyman99 (rgb99)]

The patch is no longer working. I have been hobbling along with my wired connection for several updates. With the latest upgrade to version 5.3.0-59, I tried to get it working again. I downloaded the module code from

https://github.com/abperiasamy/rtl8812AU_8821AU_linux/archive/master.zip

Then I issue the following commands to build and install it:

cd rtl8812AU_8821AU_linux-master
make
sudo make install
sudo modprobe rtl8812au
sudo cp -R . /usr/src/rtl8812AU_8821AU_linux-1.0
sudo dkms add -m rtl8812AU_8821AU_linux -v 1.0
sudo dkms build -m rtl8812AU_8821AU_linux -v 1.0
sudo dkms install -m rtl8812AU_8821AU_linux -v 1.0

I restarted the module, rebooted, it still wasn't working, but I unplugged the module from the USB cable and plugged it in again, and now it is working again.