I apologize for not knowing how to join the thread in the subject, but I'm trying to investigate similar issues. I'm using a Raspberry Pi CM3+ with a MCP2515 dtoverlay. During moments of high CAN traffic (and possibly more prevalent during high CPU usage), many RX overruns occur. The physical CAN bus signals appears sound, as I can verify the dropped frames are present and valid with an oscilloscope, so I believe the issue is related to the SocketCAN driver. Did upgrading the kernel help? To what version? Thanks for your help.
$uname -a
4.19.118-v7+ #1311 SMP Mon Apr 27 14:21:24 BST 2020 armv7l GNU/Linux
$ ip -s link show can0
2: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 200
link/can
RX: bytes packets errors dropped overrun mcast
14992 14992 71 15 71 0
TX: bytes packets errors dropped carrier collsns
1364 3028 0 0 0 0
