TX_BUFFERS
port->tx_in = (port->tx_in + 1) % TX_BUFFERS;
port->tx_out = (port->tx_out + 1) % TX_BUFFERS;
for (i = 0; i < TX_BUFFERS; i++)
for (i = 0; i < TX_BUFFERS; i++) {
struct sk_buff *tx_skbs[TX_BUFFERS];
(TX_BUFFERS + RX_BUFFERS) * BUFFER_LENGTH * ports) {
(TX_BUFFERS + RX_BUFFERS) * BUFFER_LENGTH * ports);
desc_t tx_descs[TX_BUFFERS];