I’m using DCAN0 on the Beaglebone Black to talk to a couple of other devices on a 125 kbps CAN bus. Everything is working fine but I had to request a can bus speed of 135 kbps (i.e. “ip link set can0 up type can bitrate 135000”) in order to get DCAN0 actually running at 125kbps. I’ve verified with a scope that the bit time is 8us when I set the bus speed to 135kbps. In fact, further testing at different speeds showed that in order to get any particular bus speed, I had to consistently command a speed 8.67% higher.
Has anyone else encountered this problem? Can anyone offer a suggestion as to what might cause this behavior? I’ve seen this on both a Rev A5A board and a RevC board. I’ve also tried different images to no effect.