From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH] Make virtio_net support carrier detection Date: Fri, 13 Mar 2009 08:09:49 +1030 Message-ID: <200903130809.49523.rusty@rustcorp.com.au> References: <200903121946.24847.rusty@rustcorp.com.au> <1295ed070903120547q431b5b40n71b8d2e98719e18d@mail.gmail.com> <20090312.055235.56926675.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: pktoss@gmail.com, dcbw@redhat.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from ozlabs.org ([203.10.76.45]:44413 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753103AbZCLVj4 (ORCPT ); Thu, 12 Mar 2009 17:39:56 -0400 In-Reply-To: <20090312.055235.56926675.davem@davemloft.net> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Thursday 12 March 2009 23:22:35 David Miller wrote: > Not adding a link state handler to virtio_net for pompous reasons like > some theoretical "clean design" claim is idiotic, and in the end bad > for users who are using existing versions of NetworkManager. We really don't know if there's a carrier: virtio_net doesn't support it (yet). Dan said we can't return "don't know", but he's wrong: you get -EOPNOTSUPP from ETHTOOL_GLINK. That surely gives userspace the best possible information. > If the link is always on, you should make that explicit by providing > a link state handler, and making sure it always returns true. "If". We've discussed adding a virtio_net feature to indicate link status, which implies that it's *not* always on. Rusty.