Hi,

Can somebody provide input to my query?

Thanks,
Nitin

On 23-Jan-2018, at 23:53, Saxena, Nitin 
<nitin.sax...@cavium.com<mailto:nitin.sax...@cavium.com>> wrote:
Hi,

I am running VPP on Cavium’s OCTEONTx processor which is using 
VNET_DPDK_PMD_THUNDERX driver in dpdk.  I am running into failure because 
dpdk_lib_init() and dpdk_device_setup() functions are calling 
rte_eth_dev_set_mtu() with argument hi->max_packet_bytes.

  1  Line no:112   src/plugins/dpdk/device/common.c  rte_eth_dev_set_mtu 
(xd->device_index, hi->max_packet_bytes);
  2   Line no: 674  src/plugins/dpdk/device/init.c   rte_eth_dev_set_mtu 
(xd->device_index, hi->max_packet_bytes);

I can see hi->max_packet_bytes being set to ETHERNET_MAX_PACKET_BYTES == 9216 
which is not the MTU but instead max frame size (in case of OCTEONTx)

The dpdk_lib_init() calls dpdk function: rte_eth_dev_info_get (i, &dev_info); 
to get dev_info.max_rx_pktlen

hence MTU can be calculated as

 mtu = dev_info.max_rx_pktlen - sizeof(ethernet_header_t);

which the one should be passed to rte_eth_dev_set_mtu() and not 
hi->max_packet_bytes which does not take into account what DPDK PMD driver 
passing max_rx_pktlen.

Any comment/input will be helpful?

Thanks,
Nitin


_______________________________________________
vpp-dev mailing list
vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io>
https://lists.fd.io/mailman/listinfo/vpp-dev
_______________________________________________
vpp-dev mailing list
vpp-dev@lists.fd.io
https://lists.fd.io/mailman/listinfo/vpp-dev

Reply via email to