How to implement callback for CAN Bus

maclark88

The linux socket CAN interface provides a function to register a callback when a frame is received. I am implementing a driver that needs to use this interface. I have it implemented but I am getting multiple (duplicate) frames when the remote device sends a CAN message. I have snooped on the wire and there is only ONE can message being sent. Here are the two parts of code I am working with. My guess is that there is some post-processing of the socket kernel buffer (skb) that is not getting done but I don't see any concrete examples of such an action.

Here is the registration call:
result = can_rx_register(&init_net, dev, 10 | CAN_INV_FILTER, CAN_SFF_MASK, &sc_rcv, skb, "sercan", 0);
printk( KERN_NOTICE "%s: can_rx_register() returned %d\n", DEVICE, result );

Here is the callback:
static void sc_rcv(struct sk_buff *skbr, void *data)
{
const struct can_frame *rxframe = (struct can_frame *)skbr->data;
// printk( KERN_NOTICE "%s: received a CAN packet 0x%p\n", DEVICE, rxframe);

The callback is working but it is firing multiple times (2,3... or more). Sometimes 5.

Are there any examples out in the world that show how this is implemented?