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

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

> -----Original Message-----
> From: Chas Williams [mailto:3chas3@gmail.com]
> Sent: Monday, April 2, 2018 9:57 PM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>
> Cc: Zhang, Helin <helin.zhang@intel.com>; 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 Mon, Apr 2, 2018 at 9:45 AM, Zhang, Qi Z <qi.z.zhang@intel.com> wrote:
> >
> >
> >> -----Original Message-----
> >> From: Chas Williams [mailto:3chas3@gmail.com]
> >> Sent: Monday, April 2, 2018 9:38 PM
> >> To: Zhang, Qi Z <qi.z.zhang@intel.com>
> >> Cc: Zhang, Helin <helin.zhang@intel.com>; 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 Mon, Apr 2, 2018 at 8:40 AM, Zhang, Qi Z <qi.z.zhang@intel.com>
> wrote:
> >> > 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.
> >> >> >> dev->data->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?
> >>
> >> No, I don't believe it's isolated to VF.  ixgbe_check_link() doesn't
> >> update (atomically write) the dev->data->dev_link.  After
> >> .dev_start() finishes, I need the link_status of the adapter to be set.
> >
> > I saw dev_link.link_status does be updated.
> >         err = ixgbe_check_link(hw, &speed, &link_up, 0);
> >         if (err)
> >                 goto error;
> >         dev->data->dev_link.link_status = link_up;
> 
> That doesn't fill in link_duplex, link_speed, or link_autoneg.
> 802.3ad requires that all the ports of
> the same bonding group have the same speed and duplex.  I need to be able
> to check the speed and the duplex at least (and autoneg as well).

OK, I'm not sure if it is better to call this at rte_eth_dev_start
So far we have below code.
if (dev->data->dev_conf.intr_conf.lsc == 0) {
		RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->link_update, -ENOTSUP);
		(*dev->dev_ops->link_update)(dev, 0);
	}
Can we just remove the lsc check.
I'd like to see other people's comments.

> 
> >
> >> I can't wait until I hope the first
> >> interrupt has happened that would update
> >> dev->data->dev_link.  How long would I wait?  I don't really care if
> >> the link is down,
> >> or up, or whatever, but it can't be partially filled in.  Bonding (in
> >> 802.3ad) wants the
> >> links to be similarly configured.
> >>
> >> >
> >> > 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
> >> >> >