From: Ajit Khaparde <ajit.khaparde@broadcom.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>,
Thomas Monjalon <thomas@monjalon.net>,
Dengdui Huang <huangdengdui@huawei.com>,
dev@dpdk.org, ferruh.yigit@amd.com, aman.deep.singh@intel.com,
yuying.zhang@intel.com, andrew.rybchenko@oktetlabs.ru,
liuyonglong@huawei.com, fengchengwen@huawei.com,
haijie1@huawei.com, lihuisong@huawei.com
Subject: Re: [PATCH 0/3] support setting lanes
Date: Mon, 18 Mar 2024 15:55:54 -0700 [thread overview]
Message-ID: <CACZ4nhsxz1HTJpP48z5v6T2z5Xf25My9UmXP1y75L1H-brNMBA@mail.gmail.com> (raw)
In-Reply-To: <20240318144210.2b14bd5b@hermes.local>
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On Mon, Mar 18, 2024 at 2:42 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
>
> On Mon, 18 Mar 2024 14:26:33 -0700
> Damodharam Ammepalli <damodharam.ammepalli@broadcom.com> wrote:
>
> > On Mon, Mar 18, 2024 at 7:56 AM Thomas Monjalon <thomas@monjalon.net> wrote:
> > >
> > > 12/03/2024 08:52, Dengdui Huang:
> > > > Some speeds can be achieved with different number of lanes. For example,
> > > > 100Gbps can be achieved using two lanes of 50Gbps or four lanes of 25Gbps.
> > > > When use different lanes, the port cannot be up.
> > >
> > > I'm not sure what you are referring to.
> > > I suppose it is not PCI lanes.
> > > Please could you link to an explanation of how a port is split in lanes?
> > > Which hardware does this?
> > >
> > >
> > >
> > This is a snapshot of 100Gb that the latest BCM576xx supports.
> > 100Gb (NRZ: 25G per lane, 4 lanes) link speed
> > 100Gb (PAM4-56: 50G per lane, 2 lanes) link speed
> > 100Gb (PAM4-112: 100G per lane, 1 lane) link speed
> >
> > Let the user feed in lanes=< integer value> and the NIC driver decides
> > the matching combination speed x lanes that works. In future if a new speed
> > is implemented with more than 8 lanes, there wouldn't be a need
> > to touch this speed command. Using separate lane command would
> > be a better alternative to support already shipped products and only new
> > drivers would consider this lanes configuration, if applicable.
> >
>
> The DPDK does not need more driver specific knobs.
> Shouldn't the PMD be able to auto negotiate the speed?
Yes. Its possible to auto negotiate. And that's the default.
Even for the lane count, a default number can be arrived at.
> What does Linux do?
ethtool has been extended a while ago to allow configuring the number
of lanes along with speed and other settings.
But as usual, autoneg is possible.
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next prev parent reply other threads:[~2024-03-18 22:56 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-12 7:52 Dengdui Huang
2024-03-12 7:52 ` [PATCH 1/3] ethdev: " Dengdui Huang
2024-03-19 3:02 ` Stephen Hemminger
2024-03-20 1:16 ` huangdengdui
2024-03-12 7:52 ` [PATCH 2/3] net/hns3: " Dengdui Huang
2024-03-12 7:52 ` [PATCH 3/3] app/testpmd: " Dengdui Huang
2024-03-15 21:47 ` Damodharam Ammepalli
2024-03-19 2:38 ` huangdengdui
2024-03-22 7:09 ` [PATCH v2 0/6] " Dengdui Huang
2024-03-22 7:09 ` [PATCH v2 1/6] ethdev: " Dengdui Huang
2024-03-22 13:58 ` Thomas Monjalon
2024-03-22 15:15 ` Ajit Khaparde
2024-03-22 17:32 ` Tyler Retzlaff
2024-03-22 22:30 ` Damodharam Ammepalli
2024-03-25 6:24 ` huangdengdui
2024-03-25 9:30 ` Thomas Monjalon
2024-03-25 21:14 ` Damodharam Ammepalli
2024-03-26 1:42 ` lihuisong (C)
2024-03-26 3:45 ` Ajit Khaparde
2024-03-26 10:30 ` Thomas Monjalon
2024-03-26 11:15 ` lihuisong (C)
2024-03-26 13:47 ` Ajit Khaparde
2024-03-26 18:11 ` Ajit Khaparde
2024-03-26 18:21 ` Damodharam Ammepalli
2024-03-30 11:38 ` huangdengdui
2024-04-01 20:07 ` Thomas Monjalon
2024-04-01 22:29 ` Damodharam Ammepalli
2024-04-02 8:37 ` huangdengdui
2024-04-02 15:28 ` Stephen Hemminger
2024-04-04 13:45 ` Ferruh Yigit
2024-03-29 3:25 ` lihuisong (C)
2024-03-22 7:09 ` [PATCH v2 2/6] test: updated UT for " Dengdui Huang
2024-03-22 7:09 ` [PATCH v2 3/6] ethdev: add function to parse link mode info Dengdui Huang
2024-03-22 7:09 ` [PATCH v2 4/6] net/hns3: use parse link mode info function Dengdui Huang
2024-03-22 7:09 ` [PATCH v2 5/6] net/hns3: support setting lanes Dengdui Huang
2024-03-22 7:09 ` [PATCH v2 6/6] app/testpmd: " Dengdui Huang
2024-04-04 13:58 ` [PATCH v2 0/6] " Ferruh Yigit
2024-05-16 12:48 ` huangdengdui
2024-03-18 14:56 ` [PATCH 0/3] " Thomas Monjalon
2024-03-18 21:26 ` Damodharam Ammepalli
2024-03-18 21:42 ` Stephen Hemminger
2024-03-18 22:55 ` Ajit Khaparde [this message]
2024-03-20 11:41 ` Thomas Monjalon
2024-03-20 12:31 ` Ferruh Yigit
2024-03-21 2:02 ` huangdengdui
2024-03-21 8:28 ` Thomas Monjalon
2024-03-22 2:28 ` huangdengdui
2024-03-22 4:38 ` Jerin Jacob
2024-03-22 5:25 ` Ajit Khaparde
2024-03-22 5:51 ` Jerin Jacob
2024-03-22 13:51 ` Thomas Monjalon
2024-03-25 14:04 ` Jerin Jacob
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