mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Andrew Lunn <andrew@lunn.ch>
To: Qingtao Cao <qingtao.cao.au@gmail.com>
Cc: Qingtao Cao <qingtao.cao@digi.com>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Russell King <linux@armlinux.org.uk>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] net: phy: marvell: avoid bringing down fibre link when autoneg is bypassed
Date: Thu, 3 Oct 2024 16:30:19 +0200	[thread overview]
Message-ID: <30f9c0d0-499c-47d6-bdf2-a86b6d300dbf@lunn.ch> (raw)
In-Reply-To: <20241003022512.370600-1-qingtao.cao@digi.com>

On Thu, Oct 03, 2024 at 12:25:12PM +1000, Qingtao Cao wrote:
> On 88E151x the SGMII autoneg bypass mode defaults to be enabled. When it is
> activated, the device assumes a link-up status with existing configuration
> in BMCR, avoid bringing down the fibre link in this case
> 
> Test case:
> 1. Two 88E151x connected with SFP, both enable autoneg, link is up with speed
>    1000M
> 2. Disable autoneg on one device and explicitly set its speed to 1000M
> 3. The fibre link can still up with this change, otherwise not.

What is actually wrong here?

If both ends are performing auto-neg, i would expect a link at the
highest speeds both link peers support.

If one peer is doing autoneg, the other not, i expect link down, this
is not a valid configuration, since one peer is going to fail to
auto-neg.

If both peers are using forced 1000M, i would expect a link.

   Andrew

  parent reply	other threads:[~2024-10-03 14:30 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-03  2:25 Qingtao Cao
2024-10-03  4:39 ` Parthiban.Veerasooran
2024-10-03 14:30 ` Andrew Lunn [this message]
2024-10-03 15:13   ` Russell King (Oracle)
     [not found]   ` <CAPcThSHa82QDT6sSrqcGMf7Zx4J15P7KpgfnD-LjJQi0DFh7FA@mail.gmail.com>
2024-10-04 13:26     ` Andrew Lunn
2024-10-04 13:42       ` Russell King (Oracle)
     [not found]         ` <CAPcThSHA3bfvwbHWtL2HrDtv=d9z9vGape94J7Pucq65csHN3A@mail.gmail.com>
2024-10-05 16:42           ` Andrew Lunn

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=30f9c0d0-499c-47d6-bdf2-a86b6d300dbf@lunn.ch \
    --to=andrew@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=hkallweit1@gmail.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=qingtao.cao.au@gmail.com \
    --cc=qingtao.cao@digi.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®