From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A1CAC4332F for ; Tue, 8 Mar 2022 10:06:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345629AbiCHKHp (ORCPT ); Tue, 8 Mar 2022 05:07:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236509AbiCHKHn (ORCPT ); Tue, 8 Mar 2022 05:07:43 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB36A424AA for ; Tue, 8 Mar 2022 02:06:47 -0800 (PST) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nRWjt-0000Ie-Cn; Tue, 08 Mar 2022 11:06:45 +0100 Received: from ore by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1nRWjs-0004da-Iq; Tue, 08 Mar 2022 11:06:44 +0100 Date: Tue, 8 Mar 2022 11:06:44 +0100 From: Oleksij Rempel To: Vladimir Oltean Cc: Woojung Huh , Andrew Lunn , Florian Fainelli , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Vivien Didelot , kernel@pengutronix.de, Jakub Kicinski , UNGLinuxDriver@microchip.com, "David S. Miller" Subject: Re: [PATCH net-next v2 1/1] net: dsa: microchip: ksz9477: implement MTU configuration Message-ID: <20220308100644.GA5189@pengutronix.de> References: <20220223084055.2719969-1-o.rempel@pengutronix.de> <20220223233833.mjknw5ko7hpxj3go@skbuf> <20220224045936.GB4594@pengutronix.de> <20220224093329.hssghouq7hmgxvwb@skbuf> <20220224093827.GC4594@pengutronix.de> <20220224094657.jzhvi67ryhuipor4@skbuf> <20220225114740.GA27407@pengutronix.de> <20220225115802.bvjd54cwwk6hjyfa@skbuf> <20220225125430.GB27407@pengutronix.de> <20220225163543.vnqlkltgmwf4vlmm@skbuf> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220225163543.vnqlkltgmwf4vlmm@skbuf> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 10:48:47 up 87 days, 18:34, 88 users, load average: 0.25, 0.29, 0.22 User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 25, 2022 at 06:35:43PM +0200, Vladimir Oltean wrote: > On Fri, Feb 25, 2022 at 01:54:30PM +0100, Oleksij Rempel wrote: > > > No bridge, why create a bridge? And even if you do, why add lan5 to it? > > > The expectation is that standalone ports still remain functional when > > > other ports join a bridge. > > > > No, lan5 is not added to the bridge, but stops functioning after creating > > br with lan1 or any other lanX > > Please take time to investigate the problem and fix it. ack > > > I was saying: > > > > > > ip link set lan1 up > > > ip link add link lan1 name lan1.5 type vlan id 5 > > > ip addr add 172.17.0.2/24 dev lan1.5 && ip link set lan1.5 up > > > iperf3 -c 172.17.0.10 > > > > It works. > > This is akin to saying that without any calls to ksz9477_change_mtu(), > just writing VLAN_ETH_FRAME_LEN + ETH_FCS_LEN into REG_SW_MTU__2 is > sufficient to get VLAN-tagged MTU-sized packets to pass through the CPU > port and the lan1 user port. > > So my question is: is this necessary? > > if (dsa_is_cpu_port(ds, port)) > new_mtu += KSZ9477_INGRESS_TAG_LEN; > No. I did some extra tests with following results: REG_SW_MTU__2 should be configured to 1518 to pass 1514 frame. Independent if the frame is passed between external ports or external to CPU port. So, I assume, ETH_FRAME_LEN + ETH_FCS_LEN should be used instead of VLAN_ETH_FRAME_LEN + ETH_FCS_LEN. Correct? Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |