Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751616AbaLRTVd (ORCPT ); Thu, 18 Dec 2014 14:21:33 -0500 Received: from mga11.intel.com ([192.55.52.93]:48052 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751022AbaLRTVc (ORCPT ); Thu, 18 Dec 2014 14:21:32 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,602,1413270000"; d="scan'208";a="650056871" Message-ID: <5493293A.2000802@intel.com> Date: Thu, 18 Dec 2014 11:21:30 -0800 From: John Fastabend User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: Roopa Prabhu , "Varlese, Marco" CC: "netdev@vger.kernel.org" , Thomas Graf , Jiri Pirko , "sfeldma@gmail.com" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH net-next v2 1/1] net: Support for switch port configuration References: <5492E85C.6010802@cumulusnetworks.com> <5492EFC3.8030102@cumulusnetworks.com> <549313B8.6050102@cumulusnetworks.com> <54931969.7040209@cumulusnetworks.com> In-Reply-To: <54931969.7040209@cumulusnetworks.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/18/2014 10:14 AM, Roopa Prabhu wrote: > On 12/18/14, 10:02 AM, Varlese, Marco wrote: >> Removed unnecessary content for ease of reading... >> >>>>>>>> +/* Switch Port Attributes section */ >>>>>>>> + >>>>>>>> +enum { >>>>>>>> + IFLA_ATTR_UNSPEC, >>>>>>>> + IFLA_ATTR_LEARNING, >>>>>>> Any reason you want learning here ?. This is covered as part of >>>>>>> the bridge setlink attributes. >>>>>>> >>>>>> Yes, because the user may _not_ want to go through a bridge >>>>>> interface >>>>> necessarily. >>>>> But, the bridge setlink/getlink interface was changed to accommodate >>> 'self' >>>>> for exactly such cases. >>>>> I kind of understand your case for the other attributes (these are >>>>> per port settings that switch asics provide). >>>>> >>>>> However, i don't understand the reason to pull in bridge attributes here. >>>>> >>>> Maybe, I am missing something so you might help. The learning attribute - >>> in my case - it is like all other attributes: a port attribute (as you said, port >>> settings that the switch provides per port). >>>> So, what I was saying is "why the user shall go through a bridge to configure >>> the learning attribute"? From my perspective, it is as any other attribute and >>> as such configurable on the port. >>> >>> Thinking about this some more, i don't see why any of these attributes >>> (except loopback. I dont understand the loopback attribute) cant be part of >>> the birdge port attributes. >>> >>> With this we will end up adding l2 attributes in two places: the general link >>> attributes and bridge attributes. >>> >>> And since we have gone down the path of using ndo_bridge_setlink/getlink >>> with 'self'....we should stick to that for all l2 attributes. >>> >>> The idea of overloading ndo_bridge_set/getlink, was to have the same set of >>> attributes but support both cases where the user wants to go through the >>> bridge driver or directly to the switch port driver. So, you are not really going >>> through the bridge driver if you use 'self' and ndo_bridge_setlink/getlink. >>> >> Roopa, one of the comments I got from Thomas Graf on my v1 patch >> was that your patch and mine were supplementary ("I think Roopa's >> patches are supplementary. Not all switchdev users will be backed >> with a Linux Bridge. I therefore welcome your patches very >> much")... I also understood by others that the patch made sense for >> the same reason. I simply do not understand why these attributes >> (and maybe others in the future) could not be configured directly >> on a standard port but have to go through a bridge. >> > ok, i am very confused in that case. The whole moving of bridge > attributes from the bridge driver to rtnetlink.c was to make the > bridge attributes accessible to any driver who wants to set l2/bridge > attributes on their switch ports. So, its unclear to me why we are > doing this parallel thing again. This move to rtnetlink.c was done > during the recent rocker support. so, maybe scott/jiri can elaborate > more. Not sure if this will add to the confusion or help. But you do not need to have the bridge.ko loaded or netdev's attached to a bridge to use the setlink/getlink ndo ops and netlink messages. This was intentionally done. Its already used with NIC devices to configure embedded bridge settings such as VEB/VEPA. I think I'm just repeating Roopa though. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/