Question

The syntax for netif_napi_add is:

netif_napi_add(struct net_device *dev, struct napi_struct *napi,int (*poll)(struct napi_struct *, int), int weight)

It is used for initializing the napi structure. The problem is, when I use the function as:

netif_napi_add(wdev,rnapi,rrpoll(rnapi,20),16);

It’s giving me a compilation warning:

warning: passing argument 3 of ‘netif_napi_add’ makes pointer from integer without a cast
/usr/src/linux-2.6.34.10-0.6/include/linux/netdevice.h:1089:6: note: expected ‘int (*)(struct napi_struct *, int)’ but argument is of type ‘int’

How do I fix it?

Answer 1

The third argument to netif_napi_add, int (*poll)(struct napi_struct *, int), is a function pointer named poll that points to a function that takes a struct napi_struct * and an int and returns an int. You’re calling rrpoll directly and passing its return value (an int) to netif_napi_add, instead of a function pointer. You probably want to just pass rrpoll to the function directly:

netif_napi_add(wdev, rnapi, &rrpoll, 16);