Ethernet: how to disable gigabit support

From: Pavel Machek
Date: Thu Feb 05 2015 - 15:25:36 EST


Hi!

This happened on more than one project: there's gigabit-capable chip,
but the connector is not designed for gigabit speed.

I'd like to have speed autonegotiation, but not offer gigabit (as it
will not work).

Is there way to do that without hacking the kernel? Should mii-tool do
that?

Thanks,
Pavel

root@ib8315:~# mii-tool.net-tools -A 100baseTx,10baseT eth1
restarting autonegotiation...
root@ib8315:~# [32432.443883] libphy: mdio@e0024520:01 - Link is Down

root@ib8315:~# [32435.447863] libphy: mdio@e0024520:01 - Link is Up - 1000/Full

root@ib8315:~# mii-tool.net-tools -v eth1
eth1: negotiated 1000baseT-FD flow-control, link ok
product info: vendor 00:01:c1, model 3 rev 1
basic mode: autonegotiation enabled
basic status: autonegotiation complete, link ok
capabilities: 1000baseT-FD 100baseTx-FD 100baseTx-HD
10baseT-FD 10baseT-HD
advertising: 1000baseT-FD 100baseTx-FD 100baseTx-HD
10baseT-FD 10baseT-HD
link partner: 1000baseT-FD 100baseTx-FD 100baseTx-HD
10baseT-FD 10baseT-HD flow-control
root@ib8315:~# mii-tool.net-tools -V
$Id: mii-tool.c,v 1.9 2006/09/27 20:59:18 ecki Exp $
(Author: David Hinds based on Donald Becker's mii-diag)
net-tools 1.60
root@ib8315:~#

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/