[dpdk-dev] [PATCH v1] examples/l3fwd: fix jumbo packet drop issue

[rohit.raj@nxp.com]

From: Rohit Raj <rohit.raj@nxp.com>

l3fwd uses mbufs with 2KB data size. If we enable jumbo packets, it is
not able to store packets with size greater than 2KB, hence these
packets are dropped.

This patch fixes this issue by enabling scatter for jumbo packet, if
it is supported by NIC.

If scatter is not supported by NIC and max jumbo packet length is
greater than default mbuf data size, then application exits with
proper error message.

Fixes: f68aad7904f ("examples/l3fwd: update")

Signed-off-by: Rohit Raj <rohit.raj@nxp.com>
Signed-off-by: Sachin Saxena <sachin.saxena@nxp.com>
Signed-off-by: Vanshika Shukla <vanshika.shukla@nxp.com>
---
 examples/l3fwd/main.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
index 4cb800aa15..6aaaa8ecb5 100644
--- a/examples/l3fwd/main.c
+++ b/examples/l3fwd/main.c
@@ -1035,6 +1035,20 @@ l3fwd_poll_resource_setup(void)
 				"Error during getting device (port %u) info: %s\n",
 				portid, strerror(-ret));
 
+		/* Enable Receive side SCATTER, if supported by NIC,
+		 * when jumbo packet is enabled.
+		 */
+		if (local_port_conf.rxmode.offloads &
+				DEV_RX_OFFLOAD_JUMBO_FRAME){
+			if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_SCATTER)
+				local_port_conf.rxmode.offloads |=
+						DEV_RX_OFFLOAD_SCATTER;
+			else if (local_port_conf.rxmode.max_rx_pkt_len >
+					RTE_MBUF_DEFAULT_DATAROOM)
+				rte_exit(EXIT_FAILURE,
+					"Max packet length greater than default MBUF size\n");
+		}
+
 		if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
 			local_port_conf.txmode.offloads |=
 				DEV_TX_OFFLOAD_MBUF_FAST_FREE;
-- 
2.17.1