From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: what's in a bus_info Date: Fri, 4 Nov 2011 17:07:05 -0700 Message-ID: <20111104170705.0553b8cf@nehalam.linuxnetplumber.net> References: <4EB466CB.2040506@hp.com> <1320447726.2753.30.camel@bwh-desktop> <4EB475CC.1000601@hp.com> <1320450167.2753.39.camel@bwh-desktop> <4EB47DB1.2000005@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Ben Hutchings , netdev@vger.kernel.org, rusty@rustcorp.com.au, mst@redhat.com To: Rick Jones Return-path: Received: from mail.vyatta.com ([76.74.103.46]:60399 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751747Ab1KEAHH (ORCPT ); Fri, 4 Nov 2011 20:07:07 -0400 In-Reply-To: <4EB47DB1.2000005@hp.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 04 Nov 2011 17:05:05 -0700 Rick Jones wrote: > On 11/04/2011 04:42 PM, Ben Hutchings wrote: > > On Fri, 2011-11-04 at 16:31 -0700, Rick Jones wrote: > > >> I guess that wraps back around to the question of whether there is a > >> "standard" for what should be in bus_info. And if it is impractical to > >> get the PCI bus information, > > > > I'm not that familiar with virtio, but would I be right in thinking that > > the virtio 'bus' device is likely to be the child of a PCI device? So > > then you mgiht want to get bus_name() for the grandparent of the net > > device: > > dev_dev = dev->dev.parent->parent; > > (possibly checking for nulls). > > I'll take a look. > > > If there's some reasonable way to distinguish a 'real' from a virtual > > bus then we could have the generic implementation try to follow parents > > until it finds a bus device. However I think the device model > > maintainers have been gradually moving away from the bus/class > > distinction and so we may not be able to do that. > > > >> whether it is better to return virtioN or > >> ethN. Or perhaps something else entirely. > > [...] > > > > Returning the device name seems entirely unhelpful since the user > > already has that. 'virtioN' is perhaps not much better though. > > Agreed, but thought I should ask :) My view of bus_info, is that it is an informational string for administrators. Tools shouldn't depend on the value. If a tool wants to find out about the physical device, then it should readlink the value of /sys/class/net/ethX/device