diff options
| author |   Jurek Matuszewski <jurekm@cisco.com> | 2016-03-28 15:15:15 -0400 |
|---|---|---|
| committer |   Gerrit Code Review <gerrit@fd.io> | 2016-03-29 08:59:46 +0000 |
| commit | a69318b7f72cf32df32f2744e4a386a8274094de (patch) | |
| tree | e0a0a7af563278dbe3eeacc981844e24e6850e94 | |
| parent | ad8b4728cbe40057f9a5809cdb0cd5adc629ad67 (diff) | |
Increment MRU if hardware supports CRC stripping
Change-Id: I46bd007c3c75e5fb872c1beba557e6140fa8d715
Signed-off-by: Todd Foggoa (tfoggoa) <tfoggoa@cisco.com>
| -rw-r--r-- | vnet/vnet/devices/dpdk/init.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/vnet/vnet/devices/dpdk/init.c b/vnet/vnet/devices/dpdk/init.c index 8bb253a3a66..d57f6c1a594 100644 --- a/vnet/vnet/devices/dpdk/init.c +++ b/vnet/vnet/devices/dpdk/init.c @@ -472,9 +472,33 @@ dpdk_lib_init (dpdk_main_t * dm) * Otherwise rte_eth_dev_configure() will fail and the port will * not be available. */ - xd->port_conf.rxmode.max_rx_pkt_len = - (ETHERNET_MAX_PACKET_BYTES > dev_info.max_rx_pktlen) ? - dev_info.max_rx_pktlen : ETHERNET_MAX_PACKET_BYTES; + if (ETHERNET_MAX_PACKET_BYTES > dev_info.max_rx_pktlen) + { + /* + * This device does not support the platforms's max frame + * size. Use it's advertised mru instead. + */ + xd->port_conf.rxmode.max_rx_pkt_len = dev_info.max_rx_pktlen; + } + else + { + xd->port_conf.rxmode.max_rx_pkt_len = ETHERNET_MAX_PACKET_BYTES; + + /* + * Some platforms do not account for Ethernet FCS (4 bytes) in + * MTU calculations. To interop with them increase mru but only + * if the device's settings can support it. + */ + if ((dev_info.max_rx_pktlen >= (ETHERNET_MAX_PACKET_BYTES + 4)) && + xd->port_conf.rxmode.hw_strip_crc) + { + /* + * Allow additional 4 bytes (for Ethernet FCS). These bytes are + * stripped by h/w and so will not consume any buffer memory. + */ + xd->port_conf.rxmode.max_rx_pkt_len += 4; + } + } /* * DAW-FIXME: VMXNET3 driver doesn't support jumbo / multi-buffer pkts |