From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH] bonding:update speed/duplex for NETDEV_CHANGE Date: Mon, 31 Oct 2011 18:15:06 +0000 Message-ID: <1320084906.2735.9.camel@bwh-desktop> References: <4EAE0D9A.9060408@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , , , To: Weiping Pan Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, 2011-10-31 at 22:19 +0800, Weiping Pan wrote: > Zheng Liang(lzheng@redhat.com) found a bug that if we config bonding with > arp monitor, sometimes bonding driver cannot get the speed and duplex from > its slaves, it will assume them to be 100Mb/sec and Full, please see > /proc/net/bonding/bond0. > But there is no such problem when uses miimon. > > (Take igb for example) > I find that the reason is that after dev_open() in bond_enslave(), > bond_update_speed_duplex() will call igb_get_settings() > , but in that function, > it runs ethtool_cmd_speed_set(ecmd, -1); ecmd->duplex = -1; > because igb get an error value of status. > So even dev_open() is called, but the device is not really ready to get its > settings. > > Maybe it is safe for us to call igb_get_settings() only after > this message shows up, that is "igb: p4p1 NIC Link is Up 1000 Mbps Full Duplex, > Flow Control: RX". [...] For any device with autonegotiation enabled, you generally cannot get the speed and duplex settings until the link is up. While the link is down, you may see a value of 0, ~0, or the best mode currently advertised. So I think that the bonding driver should avoid updating the slave speed and duplex values whenever autoneg is enabled and the link is down. 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.