Dkms does not rebuild WiFi driver for t3u after kernel update

Troubleshooting
1

Hi there,

Having some troubles with module rebuild via dkms and seeking for advice.

I successfully installed the driver for the t3u tplink WiFi dongle.

Whenever I update the kernel (via apt upgrade) and reboot my machine (pc native x86), I lose WiFi as the kernel module doesn’t get rebuilt, although DKMS should take care of this.

To work around this, I have to plugin my network cable, restart my machine and reinstall via the following:

sudo apt-get install --reinstall linux-headers-$(uname -r)

Then DKMS kicks in and rebuild the module.

After another reboot (network cable removed again), I have WiFi working again.

I initially installed the WiFi driver via:

git clone "https://github.com/RinCat/RTL88x2BU-Linux-Driver.git" /usr/src/rtl88x2bu-git
sed -i 's/PACKAGE_VERSION="@PKGVER@"/PACKAGE_VERSION="git"/g' /usr/src/rtl88x2bu-git/dkms.conf
dkms add -m rtl88x2bu -v git
dkms autoinstall

How can I make sure that DKMS rebuilds the module after a kernel update but before a reboot so WiFi doesn’t stop working?

Thanks
T

2

If I’m not mistaken, it should be possible to create some hook configs to force dkms during kernel update. @MichaIng knows for sure.

3 
sudo apt-get install --reinstall your kernel module

That should start the DKMS rebuild

This link shows there might be a dkms module in the source for your driver

4

As I said above, the rebuilt works but only AFTER the reboot of my machine and not during the kernel update.

And AFTER the reboot, I have lost WiFi already as the driver didn’t survive the kernel update.

So I can only rebuild when plugging in the network cable again (as I can pull what is required). Not how it should work.

5

Which SBC/hardware do you use? DKMS should ship the script /etc/kernel/postinst.d/dkms to rebuild modules on kernel installs/upgrades. Is the script there and can you see it being executed when the kernel package is upgraded?

6

Yes the script is there, but no, it wasn’t executed automatically after a kernel update (on two occasions)

I had to execute manually:

sudo apt-get install --reinstall linux-headers-$(uname -r)

But this only worked after a reboot as the new kernel was loaded (and not just installed). I had to plugin the network cable as WiFi was no longer working after the reboot (which I would like to avoid)

Is there any way to test a kernel update or revert to an older version to replicate/ reproduce and not to wait for the next update whenever this will be?