RX_RING_SIZE
for (i=0; i<RX_RING_SIZE; i++) {
for (i = 0; i < RX_RING_SIZE; i++) {
sc->rx_desc = kmalloc(sizeof(struct epic_rx_desc)*RX_RING_SIZE,
#define RX_RING_MASK (RX_RING_SIZE - 1)
struct epic_rx_buffer rx_buffer[RX_RING_SIZE];