[dpdk-dev] [PATCH v2] net/liquidio fixes unable to update linfo var

[chuhong yao <ych@panath.cn>]

When I was using VPP +dpdk-18.02+liqudio CN23xx,
I encountered such a bug.
When VPP called dpdk_device_start to initialize DPDK liqudio drive,
I found that initialization failed.
The reason for the failure is that VF MTU > PF MTU,
but PF MTU has been modified to 9600 (> VF MTU).
Finally, I am location that DPDK liqudio drive
cannot get the correct PF driver to liqudio network card.
It is due to the fact that when VPP calls dpdk_device_start to
initialize DPDK liqudio drive,this time,
lio_dev->linfo.Link var already exists in the old value, not empty.
Cause lio_dev->linfo.Link. Link_status64 != 0
statement is set up,
and the link info is stopped directly to liqudio card,
resulting in no get accurate pf mtu.
I did a test model to reproduce the bug,
which is to add rte_eth_dev_set_mtu(portid, vf_mtu)
to the rte_eth_dev_start function when using
dpdk-18.02+liqudio CN23xx+l2fwd.
You need to make sure that 1500 < vf_mtu < pf_mtu will be available.
At this time, you will have
net_liovf[04:00.3]ERROR: lio_dev_mtu_set()
VF MTU should be >= 68 and <= 1500. Such a mistake.

Signed-off-by: chuhong yao <ych@panath.cn>
---
 drivers/net/liquidio/lio_ethdev.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/liquidio/lio_ethdev.c b/drivers/net/liquidio/lio_ethdev.c
index 0e0b5d8..50743c7 100644
--- a/drivers/net/liquidio/lio_ethdev.c
+++ b/drivers/net/liquidio/lio_ethdev.c
@@ -1405,6 +1405,9 @@ struct rte_lio_xstats_name_off {
 	/* Configure RSS if device configured with multiple RX queues. */
 	lio_dev_mq_rx_configure(eth_dev);
 
+	/* Before update the link info, must set linfo.link.link_status64 to 0. */
+	lio_dev->linfo.link.link_status64 = 0;
+
 	/* start polling for lsc */
 	ret = rte_eal_alarm_set(LIO_LSC_TIMEOUT,
 				lio_sync_link_state_check,
-- 
1.8.3.1