beaglebone black can1 broken by update

Hi all,

I have a bbb based on the Debian Bullseye Minimal Image 2023-10-07, which communicates over the can1 interface. It’s been running fine for well over a year now. However, after a recent power outage, can communication stopped. Everything else was working perfectly.

Looking into it, I found the can1 interface had disapeared (as reported by ifconfig, dmesg and journalctl). I figured the power outage had corrupted something so I grabbed a new sd card, flashed a new image (Debian Bookworm Minimal Image 2023-10-07) and can1 was back. Good.
After various configurations and updates it was gone again however, so I reflashed and rechecked and found it’s the ‘apt update’ that kills it. There were minimal other changes prior to the apt update (only set timezone, static IP, root password, install hosts file).

So it wasnt the power outage at all. There appears to have been a recent package update that’s broken can1.


Looking into this further, it’s the update from kernel 5.10.168-ti-r72 to 5.10.168-ti-r76 thats breaking it.

I’ve poked around in /opt/source, but its a bit of a needle in a haystack and I’m really not sure what I’m looking for. I grepped for ‘can’, the pin names and the memory addresses, but couldnt find anything that suggested a problem.
Dmesg indicates the driver isnt being loaded - is it true that the devicetree triggers the loading of any required drivers?

My current workaround is simply to not update the device, but thats really not a proper solution.

How can I get a list of which device trees and overlays are actually being loaded?
Any advice on how to track this down would be very much appreciated.


sudo beagle-version