net/octeontx2: fix MTU when PTP is enabled

[ upstream commit 07d15d4 ]

Update MTU value based on PTP enable status and reserve eight
bytes in TX path to accommodate VLAN tags.

If PTP is enabled maximum allowed MTU is 9200 otherwise it's 9208.

Fixes: b5dc314 ("net/octeontx2: support base PTP")

Signed-off-by: Hanumanth Reddy Pothula <hpothula@marvell.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>

drivers/net/octeontx2/otx2_ethdev_ops.c

@@ -17,7 +17,8 @@ otx2_nix_mtu_set(struct rte_eth_dev *eth_dev, uint16_t mtu)
 	struct nix_frs_cfg *req;
 	int rc;
 
-	frame_size += NIX_TIMESYNC_RX_OFFSET * otx2_ethdev_is_ptp_en(dev);
+	if (dev->configured && otx2_ethdev_is_ptp_en(dev))
+		frame_size += NIX_TIMESYNC_RX_OFFSET;
 
 	/* Check if MTU is within the allowed range */
 	if (frame_size < NIX_MIN_FRS || frame_size > NIX_MAX_FRS)
@@ -560,6 +561,11 @@ otx2_nix_info_get(struct rte_eth_dev *eth_dev, struct rte_eth_dev_info *devinfo)
 	devinfo->max_vfs = pci_dev->max_vfs;
 	devinfo->max_mtu = devinfo->max_rx_pktlen - NIX_L2_OVERHEAD;
 	devinfo->min_mtu = devinfo->min_rx_bufsize - NIX_L2_OVERHEAD;
+	if (dev->configured && otx2_ethdev_is_ptp_en(dev)) {
+		devinfo->max_mtu -=  NIX_TIMESYNC_RX_OFFSET;
+		devinfo->min_mtu -=  NIX_TIMESYNC_RX_OFFSET;
+		devinfo->max_rx_pktlen -= NIX_TIMESYNC_RX_OFFSET;
+	}
 
 	devinfo->rx_offload_capa = dev->rx_offload_capa;
 	devinfo->tx_offload_capa = dev->tx_offload_capa;