From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: Re: [PATCH] 8139too: send NETDEV_CHANGE manually when autoneg is disabled Date: Thu, 7 Mar 2013 11:27:40 +0100 Message-ID: <20130307102740.GB31105@redhat.com> References: <1362596784-19443-1-git-send-email-vfalico@redhat.com> <1362601372.3126.23.camel@bwh-desktop.uk.solarflarecom.com> <20130306.155323.344491888348815531.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Cc: bhutchings@solarflare.com, netdev@vger.kernel.org, wfp5p@virginia.edu, jasowang@redhat.com, junchangwang@gmail.com, greearb@candelatech.com, ivecera@redhat.com To: David Miller Return-path: Received: from mx1.redhat.com ([209.132.183.28]:13638 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752971Ab3CGK1o (ORCPT ); Thu, 7 Mar 2013 05:27:44 -0500 Content-Disposition: inline In-Reply-To: <20130306.155323.344491888348815531.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Mar 06, 2013 at 03:53:23PM -0500, David Miller wrote: >From: Ben Hutchings >Date: Wed, 6 Mar 2013 20:22:52 +0000 > >> On Wed, 2013-03-06 at 20:06 +0100, Veaceslav Falico wrote: >>> When setting autoneg off (with any additional parameters, like >>> speed/duplex), 8139too doesn't do an interface reset, and thus doesn't >>> notify anyone that its speed/duplex might have changed (bonding and bridge >>> will not see the speed changes, per example). >>> >>> Verify if we've force_media and send notification manually, so that the >>> listeners have a chance to see the changes. It's quite ugly, however I >>> don't see anything better. >> >> Isn't this really a bug in mii_check_media()? It shouldn't shortcut the >> calls to netif_carrier_{off,on}() just because mii->force_media is set. > >I think mii_check_media() is responsible for handling this too. The mii_check_media() doesn't get called, AFAIK. The problem here is that, after we call ethtool -s eth0 autoneg off speed X, with eth0 being 8139too, the speed/autoneg options are changed via mii_ethtool_sset(), however the interface itself isn't down'ed/up'ed, and thus no NETDEV_ notifications are sent. Other drivers either explicitly reset the interface after ethtool.set_settings() call (like netxen_nic using ndo_close()/ndo_open()), do it on the logic level (tg3) without involving mii_ethtool_sset(), or just reset on their own (e100 iirc), so that most of them are responsible for somehow triggering these events. Silently changing speed can break things a bit - bonding relies on interface speeds for 802.3ad/alb/tlb/active-backup iirc, bridge relies on stp port cost etc. and they all get it via NETDEV_ notifications. So without them, they would end up with outdated data, per example (eth2 being 8139too): darkmag:~#grep 'Interface\|Speed' /proc/net/bonding/bond0 Slave Interface: eth0 Speed: 100 Mbps Slave Interface: eth2 Speed: 100 Mbps darkmag:~#ethtool -s eth2 autoneg off speed 10 darkmag:~#cat /sys/class/net/eth2/speed 10 darkmag:~#grep 'Interface\|Speed' /proc/net/bonding/bond0 Slave Interface: eth0 Speed: 100 Mbps Slave Interface: eth2 Speed: 100 Mbps However, I think that mii_check_media() is also wrong :), though I didn't really dig into it. I'll check it when I'll have time.