wlan0 not available in Debian Bookworm

I recently did a full upgrade of my OrangePi Zero boards from Stretch to Bookwork.

These boards are darn slow, but hey, at 8 bucks per board, I'll take it! One of them is my VPN, the other is my Dropbox mirror, and they work fine with only one job.

Wifi is notoriously bad in these boards due to their choice of radio chip: the XR819. Wifi was completely unusable after the upgrades, although it did work with Debian Strech.

Debugging

So first I checked nmcli for a list of devices. nmcli dev shows me wlan0 as unavailable.

Then I checked /etc/network/interfaces to make sure wlan0 is not managed there. It isn't.

nmtui is also not working. Usually you can go to "Activate a connection" to select a wifi network. It showed nothing in that menu.

Next, I checked the wpa_supplicant logs: journalctl -xeu wpa_supplicant:

wpa_supplicant[480]: Could not set interface wlan0 flags (UP): Invalid argument
wpa_supplicant[480]: WEXT: Could not set interface 'wlan0' UP
wpa_supplicant[480]: wlan0: Failed to initialize driver interface
wpa_supplicant[480]: wlan0: CTRL-EVENT-DSCP-POLICY clear_all

OK, something somewhere is calling the driver with the wrong values.

I also checked ifconfig and wlan0 was not listed there either. nmcli shows wlan0, but not available:

wlan0: unavailable
        "ST-Ericsson Wi-Fi"
        wifi (xradio_wlan), AE:84:xx:xx:xx:xx, hw, mtu 1500

So after some searching I finally found the issue: the xradio kernel module does not allow setting a MAC address from user space.

The fix? add this to /etc/NetworkManager/NetworkManager.conf:

[device]
wifi.scan-rand-mac-address=no

Now you do a systemctl restart NetworkManager and wlan0 is back and available!

I run nmcli again, and sure enough:

wlan0: disconnected
        "ST-Ericsson Wi-Fi"
        wifi (xradio_wlan), 12:42:xx:xx:xx:xx, hw, mtu 1500

p2p-dev-wlan0: disconnected
        "p2p-dev-wlan0"
        wifi-p2p, hw

I can now use nmtui again to select a network and connect. Nice!