TG3_TX_RING_SIZE
(TG3_TX_RING_SIZE << BDINFO_FLAGS_MAXLEN_SHIFT),
#define TG3_DEF_TX_RING_PENDING (TG3_TX_RING_SIZE - 1)
#define TG3_TX_RING_BYTES (sizeof(struct tg3_tx_buffer_desc) * TG3_TX_RING_SIZE)
#define NEXT_TX(N) (((N) + 1) & (TG3_TX_RING_SIZE - 1))
#define PREV_TX(N) (((N) - 1) & (TG3_TX_RING_SIZE - 1))
struct tg3_tx_buffer_desc tx_ring[TG3_TX_RING_SIZE];