Issue with mcp251x driver with host OS releases > 2.80

Product support balenaOS
1

We are running a fleet of devices using the raspberry pi 4, connected using a spi bus to the mcp2515 chip. In our systems running OS 2.65 and 2.80.3 we don’t see any issues - we see the following in the dmesg log on boot:

[ 5.128456] mcp251x spi0.1 can0: MCP2515 successfully initialized.

However, when we update the OS to anything after 2.80, for example, 2.85 or 2.88, we suddenly start seeing this fail with the message (same hardware - just change the SD card):

[    7.773570] mcp251x spi0.1: MCP251x didn't enter in conf mode after reset
[    7.773751] mcp251x spi0.1: Probe failed, err=110
[    7.773815] mcp251x: probe of spi0.1 failed with error -110

In both cases the dtoverlay is

"vc4-fkms-v3d","mcp2515-can1,oscillator=25000000,interrupt=25","uart5","i2c-rtc,pcf8523"

Obviously we’d like to stay current with the OS - thoughts?

2

Are you using custom CAN hardware or a CAN hat. I am using a couple of PICAN-M hat’s on RPi4’s with 2.88.5 and 2.87.16+rev1 without issue.

3

Hi, we’re using custom hardware using the MCP2515. Good to know it works fine with can hat.

5

Hey there, in recent OS releases you may need to use vc4-kms-v3d instead of vc4-fkms-v3d in your overlay, as this has changed in the upstream RPi firmware.

It’s possible that when the first overlay cannot be found, none of them are loaded, so your mcp2515-can1 might not be loaded at all. Can you also confirm that mcp2515-can1.dtbo is in the /mnt/boot/overlays directory of your image?