This is a list of knwon driver issues:

drivers/net/can/mcp251x.c:

  FIXME: echo support missing (requilred for IFF_ECHO)
  FIXME: increment can_stats in case of state changes
  FIXME: state changes by interrupt
  FIXME: do_set_mode not implemented (required for restart)
  FIXME: remove tx timeout callback
  FIXME: to be tested

drivers/net/can/softing/softing_main.c:

  FIXME: coding style issues!
  FIXME: check softing_flush_echo_skb and bus_off handling.
  FIXME: to be tested