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
next prev 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
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