[dpdk-dev] [PATCH v2] net/ixgbe: remove MTU setting limitation when port's stopped

[Beilei Xing]

Currently, setting MTU will fail if MTU requires the support
of scattered packets before scatter is enabled.
This patch allows setting this special MTU when device is
stopped, cause scatter will be re-configured during starting
port.

Signed-off-by: Beilei Xing <beilei.xing at intel.com>
---
v2 changes:
 - change commit log

 drivers/net/ixgbe/ixgbe_ethdev.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index fb5574e..ece5d6c 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -4812,6 +4812,7 @@ ixgbe_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 	struct rte_eth_dev_info dev_info;
 	uint32_t frame_size = mtu + ETHER_HDR_LEN + ETHER_CRC_LEN;
 	struct rte_eth_rxmode *rx_conf = &dev->data->dev_conf.rxmode;
+	struct rte_eth_dev_data *dev_data = dev->data;
 
 	ixgbe_dev_info_get(dev, &dev_info);
 
@@ -4819,13 +4820,15 @@ ixgbe_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 	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 device is started, refuse mtu that requires the support of
+	 * scattered packets when this feature has not been enabled before.
 	 */
-	if (!rx_conf->enable_scatter &&
+	if (dev_data->dev_started && !rx_conf->enable_scatter &&
 	    (frame_size + 2 * IXGBE_VLAN_TAG_SIZE >
-	     dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM))
+	     dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM)) {
+		PMD_INIT_LOG(ERR, "Stop port first.");
 		return -EINVAL;
+	}
 
 	hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 	hlreg0 = IXGBE_READ_REG(hw, IXGBE_HLREG0);
-- 
2.5.5