From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753839AbbG2TON (ORCPT ); Wed, 29 Jul 2015 15:14:13 -0400 Received: from mail.savoirfairelinux.com ([209.172.62.77]:53163 "EHLO mail.savoirfairelinux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753309AbbG2TOL (ORCPT ); Wed, 29 Jul 2015 15:14:11 -0400 Date: Wed, 29 Jul 2015 15:14:05 -0400 (EDT) From: Vivien Didelot To: David Cc: sfeldma@gmail.com, netdev , jiri@resnulli.us, Florian Fainelli , linux-kernel , kernel Message-ID: <117624450.145106.1438197245281.JavaMail.zimbra@savoirfairelinux.com> In-Reply-To: <20150729.112842.1871916445536378243.davem@davemloft.net> References: <1437954348-11859-1-git-send-email-vivien.didelot@savoirfairelinux.com> <20150729.112842.1871916445536378243.davem@davemloft.net> Subject: Re: [PATCH] net: switchdev: restrict vid range abstraction MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Mailer: Zimbra 8.6.0_GA_1153 (ZimbraWebClient - FF39 (Linux)/8.6.0_GA_1153) Thread-Topic: switchdev: restrict vid range abstraction Thread-Index: +9/jbm+w4VL15MWJi82hyc0gl89x6g== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Scott, David, On Jul 29, 2015, at 2:28 PM, David davem@davemloft.net wrote: > From: Scott Feldman > Date: Wed, 29 Jul 2015 00:31:44 -0700 > >> Since the netlink request (for example vlan add) includes the range, >> I'm not seeing how we can response with success for the satisfied >> vlans in the range, and also respond with an error for the unsatisfied >> vlans in the range. In other words, from the netlink msgs >> perspective, we need to treat a vlan range as all-or-nothing. So in >> your example, if hw can't add vlan 2, we fail the entire request to >> add range 2-5. This is where the prepare phase checks to make sure >> the entire request can be satisfied before committing to hw. I made this change in order to start restricting the bridge abstraction to switchdev, since IMHO its info flags do not add much value to the switch chip drivers perspective. While a range might be convenient to a user, exposing it to drivers is likely to end up writing the same vid_begin to vid_end for loop. > This was my concern with the change as well. > > The user asked for the range to be installed, so if any portion > of it cannot be done we must not make any changes to the HW > configuration and fail the entire request. I understand the concern with the netlink request. However, this can be confusing to someone. With the previous example: bridge vlan add dev port0 vid 2-5 master must fail for the entire range (due to the single netlink request). But: bridge vlan add dev port0 vid 2 master will silently fallback to software VLAN (assuming that the driver correctly returned -EOPNOTSUPP in the prepare phase). In other words, no changes has been committed to the hardware. Thanks, -v