From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Graf Subject: Re: [PATCH 1/3] netdev: introduce new NETIF_F_HW_SWITCH_OFFLOAD feature flag for switch device offloads Date: Sat, 6 Dec 2014 10:14:25 +0000 Message-ID: <20141206101425.GA15999@casper.infradead.org> References: <1417746401-8140-2-git-send-email-roopa@cumulusnetworks.com> <20141205224320.GA22992@casper.infradead.org> <5482B44F.2050509@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jiri@resnulli.us, sfeldma@gmail.com, jhs@mojatatu.com, bcrl@kvack.org, john.fastabend@gmail.com, stephen@networkplumber.org, linville@tuxdriver.com, nhorman@tuxdriver.com, nicolas.dichtel@6wind.com, vyasevic@redhat.com, f.fainelli@gmail.com, buytenh@wantstofly.org, aviadr@mellanox.com, netdev@vger.kernel.org, davem@davemloft.net, shm@cumulusnetworks.com, gospo@cumulusnetworks.com To: Roopa Prabhu Return-path: Received: from casper.infradead.org ([85.118.1.10]:37626 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751523AbaLFKOa (ORCPT ); Sat, 6 Dec 2014 05:14:30 -0500 Content-Disposition: inline In-Reply-To: <5482B44F.2050509@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org List-ID: On 12/05/14 at 11:46pm, Roopa Prabhu wrote: > On 12/5/14, 2:43 PM, Thomas Graf wrote: > >On 12/04/14 at 06:26pm, roopa@cumulusnetworks.com wrote: > >>From: Roopa Prabhu > >> > >>This is a generic high level feature flag for all switch asic features today. > >> > >>switch drivers set this flag on switch ports. Logical devices like > >>bridge, bonds, vxlans can inherit this flag from their slaves/ports. > >> > >>I had to use SWITCH in the name to avoid ambiguity with other feature > >>flags. But, since i have been harping about not calling it 'switch', > >>I am welcome to any suggestions :) > >> > >>An alternative to using a feature flag is to use a IFF_HW_OFFLOAD > >>in net_device_flags. > >What does this flag indicate specifically? What driver would > >implement ndo_bridge_setlink() but not set this flag? > > > >I think it should be clearly documented when this flag is to bet set. > I mentioned it as an alternative because it was there in my RFC patch. There > is no code for it yet. > And I will get rid of the comment in v2. Sorry, I was referring to NETIF_F_HW_SWITCH_OFFLOAD. I do not understand the scope of this bit/flag yet. Can you give examples when to set this bit? At what point would the existing ixgbe FDB offload set this bit? Is there a case when ndo_bridge_setlink() is implemented but this bit is not set?