From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: ETHTOOL_GSET IOCTL on GigE links Date: Fri, 01 Jun 2007 18:40:04 -0400 Message-ID: <4660A044.5090007@garzik.org> References: <46F9780F64AE9945815725F4C0C72CB803026226@hq-exch-1.corp.brocade.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-net@vger.kernel.org, netdev To: Jeff Haran Return-path: In-Reply-To: <46F9780F64AE9945815725F4C0C72CB803026226@hq-exch-1.corp.brocade.com> Sender: linux-net-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Jeff Haran wrote: > With 10/100 Mbps links it wasn't such an issue since the devices tend to > support the same forced speeds and duplexities as they are capable of > negotiating, but with GigE links that's not always the case, at least > not according to what I've read. For instance, the following doc from > Sun http://www.sun.com/blueprints/0704/817-7526.pdf says that IEEE > 802.3ab says you can't force 1000Base-T over copper media (see page 4), > whereas some other physical media allow GigE to run without > autonegotiation (there's apparently this "serdes" interface that allows > it, for instance). > > Seems like there should be another field named something like > supported_forced to indicate what can be forced on the interface. Either > that or some more SUPPORTED_* bits to indicate supported forced modes. The 'supported' field has nothing at all to do with auto-negotiation. The driver should list all possibilities in that field, even if some are ONLY supported via 'forced' selection. Jeff P.S. netdev@linux.kernel.org is a far more active list, and is where the network stack/driver developers appear.