+static int
+eth_igb_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
+{
+ uint32_t rctl;
+ struct e1000_hw *hw;
+ struct rte_eth_dev_info dev_info;
+ uint32_t frame_size = mtu + (ETHER_HDR_LEN + ETHER_CRC_LEN +
+ VLAN_TAG_SIZE);
+
+ hw = E1000_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+
+#ifdef RTE_LIBRTE_82571_SUPPORT
+ /* XXX: not bigger than max_rx_pktlen */
+ if (hw->mac.type == e1000_82571)
+ return -ENOTSUP;
+#endif
+ eth_igb_infos_get(dev, &dev_info);
+
+ /* check that mtu is within the allowed range */
+ if ((mtu < ETHER_MIN_MTU) ||
+ (frame_size > dev_info.max_rx_pktlen))
+ return -EINVAL;
+
+ /* refuse mtu that requires the support of scattered packets when this
+ * feature has not been enabled before. */
+ if (!dev->data->scattered_rx &&
+ frame_size > dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM)
+ return -EINVAL;
+
+ rctl = E1000_READ_REG(hw, E1000_RCTL);
+
+ /* switch to jumbo mode if needed */
+ if (frame_size > ETHER_MAX_LEN) {
+ dev->data->dev_conf.rxmode.jumbo_frame = 1;
+ rctl |= E1000_RCTL_LPE;
+ } else {
+ dev->data->dev_conf.rxmode.jumbo_frame = 0;
+ rctl &= ~E1000_RCTL_LPE;
+ }
+ E1000_WRITE_REG(hw, E1000_RCTL, rctl);
+
+ /* update max frame size */
+ dev->data->dev_conf.rxmode.max_rx_pkt_len = frame_size;
+
+ E1000_WRITE_REG(hw, E1000_RLPML,
+ dev->data->dev_conf.rxmode.max_rx_pkt_len);
+
+ return 0;
+}
+