Re: [dpdk-dev] [PATCH] net/ixgbe: update data->eth_link status on start

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

Hi Williams:

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Chas Williams
> Sent: Saturday, March 31, 2018 1:22 AM
> To: Zhang, Helin <helin.zhang@intel.com>
> Cc: dev@dpdk.org; Lu, Wenzhuo <wenzhuo.lu@intel.com>; Ananyev,
> Konstantin <konstantin.ananyev@intel.com>; Charles (Chas) Williams
> <chas3@att.com>
> Subject: Re: [dpdk-dev] [PATCH] net/ixgbe: update data->eth_link status on
> start
> 
> On Fri, Mar 30, 2018 at 12:30 PM, Zhang, Helin <helin.zhang@intel.com>
> wrote:
> >
> >
> >> -----Original Message-----
> >> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Chas Williams
> >> Sent: Wednesday, February 14, 2018 6:56 AM
> >> To: dev@dpdk.org
> >> Cc: Lu, Wenzhuo; Ananyev, Konstantin; Charles (Chas) Williams
> >> Subject: [dpdk-dev] [PATCH] net/ixgbe: update data->eth_link status
> >> on start
> >>
> >> From: "Charles (Chas) Williams" <chas3@att.com>
> >>
> >> dev->data->eth_link isn't updated until the first interrupt.  If a
> >> link is carrier down, then this interrupt may never happen.  Before
> >> we finished starting the PMD, call ixgbe_dev_link_update() to ensure we
> have a valid status.
> >>
> >> Signed-off-by: Chas Williams <chas3@att.com>
> >> ---
> >>  drivers/net/ixgbe/ixgbe_ethdev.c | 4 ++++
> >>  1 file changed, 4 insertions(+)
> >>
> >> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
> >> b/drivers/net/ixgbe/ixgbe_ethdev.c
> >> index 37eb668..27d29dc 100644
> >> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> >> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> >> @@ -2666,6 +2666,8 @@ ixgbe_dev_start(struct rte_eth_dev *dev)
> >>       if (err)
> >>               goto error;
> >>
> >> +     ixgbe_dev_link_update(dev, 0);
> > It is called in rte_eth_dev_start() if lsc is not enabled, and it is
> > not needed here to avoid any duplication.
> > BTW, did you see any issue or just check the code? Thanks!
> 
> Yes, I see an issue with bonding.  If LSC is enabled, then link_status isn't set
> until the first interrupt to update the link status.  If a link is down, this
> interrupt may never happen result in link_status being somewhat undefined.

Is your issue only happened on VF?
For PF, I saw ixgbe_check_link is called at ixgbe_dev_start, so link status is assume be updated.
If you think it is just missed in VF, can you implemented this in the similar way as PF?

Regards
Qi

> 
> >
> > /Helin
> >
> >> +
> >>  skip_link_setup:
> >>
> >>       if (rte_intr_allow_others(intr_handle)) { @@ -5033,6 +5035,8 @@
> >> ixgbevf_dev_start(struct rte_eth_dev *dev)
> >>
> >>       ixgbevf_dev_rxtx_start(dev);
> >>
> >> +     ixgbevf_dev_link_update(dev, 0);
> >> +
> >>       /* check and configure queue intr-vector mapping */
> >>       if (rte_intr_cap_multiple(intr_handle) &&
> >>           dev->data->dev_conf.intr_conf.rxq) {
> >> --
> >> 2.9.5
> >