Repairing Wired Connection, 5.4 LTS

[Llama]

Trying to build the Wi-Fi dirver (the history of my failure here) I lost my basic wired connection.

• The box is HP notebook.
• RTL8723DE Wi-Fi driver removed, or so I think.
• My only bootable kernel is 5.4.85 LTS.
• When I boot from the Manjaro KDE USB stick, the wired connection is OK.

No boot errors or warnings, nothing to start from. Just no wired connection. I tried to reinstall the NetworkManager from the package cache, first removing /etc/NetworkManager. Nothing changed. What can I do?

[Llama]

$ ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:7b:54:98:36 brd ff:ff:ff:ff:ff:ff

$ ip link set eth0 up
Cannot find device "eth0"

Which is no surprise, I suppose. What can I do next?

[moson]

What’s the output of lspci

Anything blacklisted here?
cat /etc/modprobe.d/*.conf

[Llama]

$ lspci
...
Ethernet controller: Realtek Semiconductor, RTL8111/8168/8411 PCI ...
Network controller: Realtek Semiconductor, RTL8723DE ...

/etc/modprobe.d $ cat *.conf
blacklist r8169

$ lspci | grep 8169
$

There is no 8169 entity in the lspci output.

[moson]

Try to remove the file containing blacklist r8169 and then reboot.

[Llama]

It helps indeed! Thank you very much!

Would you care to explain what’s happening? I’ve got another box with the same blacklist file (generated by mhwd); there’s no trouble there.

[moson]

Could it be that you uninstalled linux54-r8168 ?

r8169 is provided directly from kernel whereas r8168 is an extramodule (and separate package) with the driver provided by realtek.

It seems for some adapters r8169 is working better whereas for others they need r8168 to work properly.

When r8168 is installed and should be used rather than the “built-in” r8169 module, the r8169 module has to be blacklisted since it has precedence and would be loaded instead…

The blacklisting will be done by a mhwd script if you install the driver with mhwd.
Same is valid when the package is removed. It will only remove the blacklisting when removed via mhwd. If you uninstall the package manually, the driver will be gone but blacklisting will stay and hence it will not load the r8169 and you don’t have network.