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 17:35:37 +0100 Message-ID: <20130307163537.GA21810@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> <20130307102740.GB31105@redhat.com> <1362671555.2936.10.camel@bwh-desktop.uk.solarflarecom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Cc: David Miller , netdev@vger.kernel.org, wfp5p@virginia.edu, jasowang@redhat.com, junchangwang@gmail.com, greearb@candelatech.com, ivecera@redhat.com To: Ben Hutchings Return-path: Received: from mx1.redhat.com ([209.132.183.28]:19275 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753057Ab3CGQgC (ORCPT ); Thu, 7 Mar 2013 11:36:02 -0500 Content-Disposition: inline In-Reply-To: <1362671555.2936.10.camel@bwh-desktop.uk.solarflarecom.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Mar 07, 2013 at 03:52:35PM +0000, Ben Hutchings wrote: >On Thu, 2013-03-07 at 11:27 +0100, Veaceslav Falico wrote: >> 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. > >Does the hardware not send link interrupts if autoneg is disabled? Yes, it doesn't send them when the autoneg off is set. > >> 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): >[...] > >Yes, I get it. But on real hardware, changing speed/duplex is always >going to break the link if it's up. The link change notification should >result in kernel and userland notifications via linkwatch_do_dev(). > >(If you're testing against QEMU rather than real hardware, there could >be a bug in the emulation of link interrupts.) It's real hardware: [ 4.339413] 8139cp 0000:10:09.0: This (id 10ec:8139 rev 10) is not an 8139C+ compatible chip, use 8139too [ 4.348210] 8139too: 8139too Fast Ethernet driver 0.9.28 [ 4.350017] 8139too 0000:10:09.0 eth2: RealTek RTL8139 at 0xffffc90004574100, 00:14:d1:1f:b9:49, IRQ 21 darkmag:~#ethtool eth2 Settings for eth2: Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Advertised pause frame use: No Advertised auto-negotiation: Yes Link partner advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Link partner advertised pause frame use: Symmetric Link partner advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full darkmag:~#dmesg | tail -n 10 | grep 8139too [ 164.019622] 8139too 0000:10:09.0 eth2: link up, 100Mbps, full-duplex, lpa 0x45E1 darkmag:~#ethtool -s eth2 autoneg off speed 10 darkmag:~#dmesg | tail -n 10 | grep 8139too [ 164.019622] 8139too 0000:10:09.0 eth2: link up, 100Mbps, full-duplex, lpa 0x45E1 darkmag:~#ethtool eth2 Settings for eth2: Supports auto-negotiation: Yes Advertised link modes: Not reported Advertised pause frame use: No Advertised auto-negotiation: No Speed: 10Mb/s Duplex: Full And, obviously, bonding's not updated: darkmag:~#grep 'Interface\|Speed' /proc/net/bonding/bond0 Slave Interface: eth0 Speed: 100 Mbps Slave Interface: eth2 Speed: 100 Mbps > >Ben. > >-- >Ben Hutchings, Staff Engineer, Solarflare >Not speaking for my employer; that's the marketing department's job. >They asked us to note that Solarflare product names are trademarked. >