AGX Xavier - CANBus can not work

Hi Sir,

We were unable to communicate via CANBUS so we disconnected everything and started troubleshooting. After restarting the system (with no physical connections to the CANBUS PORT) we observed the following :

In particular, the CANBUS is receiving large amounts of “packets”, all of which are errors. When we connected an oscilloscope to the pins, we also see large amounts of activity. As you can see, out of 19.8 GB of “data” that is being received on CAN0, virtually all of it are error packets. Meanwhile, no packets are being transmitted by the CAN (TX packets is 0). Once again, this is with nothing connected to the port. Our theory is that there is some sort of interference occurring within the product, however any feedback or advice would be appreciated. Thank you.

Other information:
KERNEL VERSION: 4.9.201-tegra

Log:
log1.tgz (17.4 MB)

Thank you for your help.

Please check below thread to see if can help: CAN Transceivers on Jetson AGX Xavier - Jetson & Embedded Systems / Jetson AGX Xavier - NVIDIA Developer Forums

Hi Sir,

After rebooting the system and verifying that all the modules are loaded and registers are set (as per the link:

), the CANBus are up in a stable state, and we’re able to perform a loopback test on can0.

However, after doing some test messages using cansend, as shown below:
2022-08-09 17 46 40.jpg

We suddenly get the same runaway errors on can1
2022-08-09 17 49 08.jpg

The error is intermittent. We were unable to reproduce it on can0 again, but after a few tries, it eventually happened on can1.
When we took can1 down (via ifconfig) and back up again, the errors stopped accumulating and we were able to send on can1 without any errors. But we’re not sure if it will stay this way or if it will go through producing errors again after a while.

I hope this provides some insight.

Thank you for your help.

hello neptuneliu,

could you please setup a terminal to gather the logs when you’ve reproduce the CAN issue, i.e. $ dmesg --follow
please also share the error messages for reference, thanks

Hi Jerry,

I have attached a link to the image of the error message. Please check the attached image in the previous post.

Best Regards,
Neptune Liu

hello neptuneliu,

sorry, I check those attachments, 2022-08-09*.jpg but not see any related failures.
could you please have code block to attach logs to the discussion thread directly?
for example, <code>LOGs...</code>

2022-08-09 17 46 40.jpg

2022-08-09 17 49 08.jpg

The attached file is dmesgLog for your reference.
dmesgLog (5.3 KB)

hello neptuneliu,

here shows the failure…

[  497.839365] mttcan c320000.mttcan can1: Acknowledgement Error Detected
[  497.839499] mttcan c320000.mttcan can1: IR 0x8000000 PSR 0x77b

please review the pinmux configuration, had you configure the CAN pins as SFIO mode?

Hi Jerry,

We don’t understand what is meant by SFIO mode.

Are you able to recreate this issue on your end? If so, would you be able to troubleshoot it and come up with a clear solution?

Thank you for your help.

hello neptuneliu,

it’s pin configurations, you may have customer usage to select GPIO or SFIO, please see-also pinmux spreadsheets.
this may also due to hardware issue, please review your CAN networks. thanks