Re: [dpdk-dev] i40e rte_eth_link_get_nowait() on X722 returns wrong link_speed value 20000 instead of 10000

["Xing, Beilei" <beilei.xing@intel.com>]

> -----Original Message-----
> From: Martin Weiser [mailto:martin.weiser@allegro-packets.com]
> Sent: Tuesday, April 9, 2019 7:21 PM
> To: Xing, Beilei <beilei.xing@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>;
> dev@dpdk.org
> Subject: Re: [dpdk-dev] i40e rte_eth_link_get_nowait() on X722 returns
> wrong link_speed value 20000 instead of 10000
> 
> Hi,
> 
> just bumping this since there has been no reply at all for a long time.
> Would it be better if I opened a bug for this?

Thanks for reporting.
Yes, you can open a bug on bugzilla, and we will check it if the bug exists.

> 
> Best,
> Martin
> 
> 
> Am 22.01.19 um 16:07 schrieb Martin Weiser:
> > Hi,
> >
> > We are using a Xeon D with an integrated X722 NIC that provides two
> > ports of 8086:37d2 and two ports of 8086:37d0. All four ports show the
> > same behavior: they return a link speed value of 20000 for a 10Gbps link.
> >
> > This only seems to happen when internally the update_link_reg()
> > function in i40e_ethdev.c is used. This requires the application to
> > use the
> > rte_eth_link_get_nowait() function and not use link status change
> > interrupts.
> > If you use e.g. testpmd with the option --no-lsc-interrupt you can
> > reproduce the behavior since it will suddenly show a link speed of
> > 20000 Mbps instead of 10000 Mbps.
> >
> >
> > Here are two examples of the register values read by update_link_reg():
> >
> > A 10Gbps link which produces the wrong link speed value:
> >
> > I40E_PRTMAC_LINKSTA: 0x60000080
> > I40E_PRTMAC_MACC:    0x3d00
> >
> >
> > A 1Gbps link which produces the correct link speed value:
> >
> > I40E_PRTMAC_LINKSTA: 0x48000081
> > I40E_PRTMAC_MACC:    0x3d00
> >
> >
> > Best regards,
> > Martin
> >
> 
>