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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9C86C433E0 for ; Tue, 26 May 2020 10:00:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC12D2073B for ; Tue, 26 May 2020 10:00:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731735AbgEZKAQ (ORCPT ); Tue, 26 May 2020 06:00:16 -0400 Received: from simonwunderlich.de ([79.140.42.25]:48706 "EHLO simonwunderlich.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726804AbgEZKAN (ORCPT ); Tue, 26 May 2020 06:00:13 -0400 Received: from kero.packetmixer.de (p200300c597221100fc44a592f3d496ba.dip0.t-ipconnect.de [IPv6:2003:c5:9722:1100:fc44:a592:f3d4:96ba]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by simonwunderlich.de (Postfix) with ESMTPSA id 6206C6206B; Tue, 26 May 2020 12:00:10 +0200 (CEST) From: Simon Wunderlich To: davem@davemloft.net Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, Sven Eckelmann , Matthias Schiffer , Simon Wunderlich Subject: [PATCH 3/3] batman-adv: Revert "disable ethtool link speed detection when auto negotiation off" Date: Tue, 26 May 2020 12:00:07 +0200 Message-Id: <20200526100007.10501-4-sw@simonwunderlich.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200526100007.10501-1-sw@simonwunderlich.de> References: <20200526100007.10501-1-sw@simonwunderlich.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Sven Eckelmann The commit 8c46fcd78308 ("batman-adv: disable ethtool link speed detection when auto negotiation off") disabled the usage of ethtool's link_ksetting when auto negotation was enabled due to invalid values when used with tun/tap virtual net_devices. According to the patch, automatic measurements should be used for these kind of interfaces. But there are major flaws with this argumentation: * automatic measurements are not implemented * auto negotiation has nothing to do with the validity of the retrieved values The first point has to be fixed by a longer patch series. The "validity" part of the second point must be addressed in the same patch series by dropping the usage of ethtool's link_ksetting (thus always doing automatic measurements over ethernet). Drop the patch again to have more default values for various net_device types/configurations. The user can still overwrite them using the batadv_hardif's BATADV_ATTR_THROUGHPUT_OVERRIDE. Reported-by: Matthias Schiffer Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/bat_v_elp.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index 353e49c40e7f..0bdefa35da98 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -127,20 +127,7 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) rtnl_lock(); ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings); rtnl_unlock(); - - /* Virtual interface drivers such as tun / tap interfaces, VLAN, etc - * tend to initialize the interface throughput with some value for the - * sake of having a throughput number to export via ethtool. This - * exported throughput leaves batman-adv to conclude the interface - * throughput is genuine (reflecting reality), thus no measurements - * are necessary. - * - * Based on the observation that those interface types also tend to set - * the link auto-negotiation to 'off', batman-adv shall check this - * setting to differentiate between genuine link throughput information - * and placeholders installed by virtual interfaces. - */ - if (ret == 0 && link_settings.base.autoneg == AUTONEG_ENABLE) { + if (ret == 0) { /* link characteristics might change over time */ if (link_settings.base.duplex == DUPLEX_FULL) hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX; -- 2.20.1