From: Andrew Lunn <andrew@lunn.ch>
To: Juerg Haefliger <juerg.haefliger@canonical.com>
Cc: netdev@vger.kernel.org, woojung.huh@microchip.com
Subject: Re: lan78xx: /sys/class/net/eth0/carrier stuck at 1
Date: Wed, 21 Oct 2020 21:35:48 +0200 [thread overview]
Message-ID: <20201021193548.GU139700@lunn.ch> (raw)
In-Reply-To: <20201021170053.4832d1ad@gollum>
On Wed, Oct 21, 2020 at 05:00:53PM +0200, Juerg Haefliger wrote:
> Hi,
>
> If the lan78xx driver is compiled into the kernel and the network cable is
> plugged in at boot, /sys/class/net/eth0/carrier is stuck at 1 and doesn't
> toggle if the cable is unplugged and replugged.
>
> If the network cable is *not* plugged in at boot, all seems to work fine.
> I.e., post-boot cable plugs and unplugs toggle the carrier flag.
>
> Also, everything seems to work fine if the driver is compiled as a module.
>
> There's an older ticket for the raspi kernel [1] but I've just tested this
> with a 5.8 kernel on a Pi 3B+ and still see that behavior.
Hi Jürg
Could you check if a different PHY driver is being used when it is
built and broken vs module or built in and working.
Look at /sys/class/net/eth0/phydev/driver
I'm wondering if in the builtin case, it is using genphy, but with
modules it uses a more specific vendor driver.
Andrew
next prev parent reply other threads:[~2020-10-21 19:35 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-21 15:00 lan78xx: /sys/class/net/eth0/carrier stuck at 1 Juerg Haefliger
2020-10-21 19:35 ` Andrew Lunn [this message]
2020-10-23 6:29 ` Juerg Haefliger
2020-10-23 13:05 ` Andrew Lunn
2020-11-03 12:47 ` Juerg Haefliger
2020-11-03 15:27 ` Andrew Lunn
2020-11-06 8:56 ` Juerg Haefliger
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