[dpdk-dev] [PATCH] net/ixgbevf: remove MTU setting limitation

[David Harton <dharton@cisco.com>]

Currently, if requested MTU is bigger than mbuf size and scattered
receive is not enabled, setting MTU to that value fails.

This patch allows setting this special MTU when device is stopped,
because scattered_rx will be re-configured during next port start
and driver may enable scattered receive according new MTU value.

After this patch, driver may select different receive function
automatically after MTU set, according MTU values selected.

Signed-off-by: David Harton <dharton@cisco.com>
---
 drivers/net/ixgbe/ixgbe_ethdev.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index feec85634..0b962c8db 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -6346,20 +6346,22 @@ ixgbevf_dev_set_mtu(struct rte_eth_dev *dev, uint16_t mtu)
 {
 	struct ixgbe_hw *hw;
 	uint32_t max_frame = mtu + IXGBE_ETH_OVERHEAD;
-	struct rte_eth_rxmode *rx_conf = &dev->data->dev_conf.rxmode;
+	struct rte_eth_dev_data *dev_data = dev->data;
 
 	hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 
 	if ((mtu < ETHER_MIN_MTU) || (max_frame > ETHER_MAX_JUMBO_FRAME_LEN))
 		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->offloads & DEV_RX_OFFLOAD_SCATTER) &&
+	if (dev_data->dev_started && !dev_data->scattered_rx &&
 	    (max_frame + 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;
+	}
 
 	/*
 	 * When supported by the underlying PF driver, use the IXGBE_VF_SET_MTU
-- 
2.19.1