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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 15F67C33CAD for ; Mon, 13 Jan 2020 12:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E5C992084D for ; Mon, 13 Jan 2020 12:51:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728734AbgAMMvd (ORCPT ); Mon, 13 Jan 2020 07:51:33 -0500 Received: from mx2.suse.de ([195.135.220.15]:44914 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726480AbgAMMvc (ORCPT ); Mon, 13 Jan 2020 07:51:32 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id CEAC2ACC9; Mon, 13 Jan 2020 12:51:30 +0000 (UTC) Received: by unicorn.suse.cz (Postfix, from userid 1000) id 28CC0E3C1F; Mon, 13 Jan 2020 13:51:29 +0100 (CET) Date: Mon, 13 Jan 2020 13:51:29 +0100 From: Michal Kubecek To: netdev@vger.kernel.org Cc: Kai-Heng Feng , davem@davemloft.ne, jeffrey.t.kirsher@intel.com, "David S. Miller" , Florian Fainelli , Jiri Pirko , Pablo Neira Ayuso , Maxime Chevallier , Jakub Kicinski , Li RongQing , open list Subject: Re: [PATCH 2/2] ethtool: Call begin() and complete() in __ethtool_get_link_ksettings() Message-ID: <20200113125129.GD25361@unicorn.suse.cz> References: <20200110074159.18473-1-kai.heng.feng@canonical.com> <20200110074159.18473-2-kai.heng.feng@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200110074159.18473-2-kai.heng.feng@canonical.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 10, 2020 at 03:41:59PM +0800, Kai-Heng Feng wrote: > Device like igb gets runtime suspended when there's no link partner. We > can't get correct speed under that state: > $ cat /sys/class/net/enp3s0/speed > 1000 > > In addition to that, an error can also be spotted in dmesg: > [ 385.991957] igb 0000:03:00.0 enp3s0: PCIe link lost > > It's because the igb device doesn't get runtime resumed before calling > get_link_ksettings(). > > So let's call begin() and complete() like what dev_ethtool() does, to > runtime resume/suspend or power up/down the device properly. > > Once this fix is in place, igb can show the speed correctly without link > partner: > $ cat /sys/class/net/enp3s0/speed > -1 I agree that we definitely should make sure ->begin() and ->complete() are always called around ethtool_ops calls. But even if nesting should be safe now (for in-tree drivers, that is), I'm not really happy about calling them even in places where we positively know we are always inside a begin / complete block as e.g. vxlan or net_failover do. (And also linkinfo.c and linkmodes.c but it may be easier to call ->get_link_ksettings() directly there.) How about having two helpers: one simple for "ethtool context" where we know we already are between ->begin() and ->complete() and one with the begin/complete calls for the rest? Another interesting question is if any of the callers which do not have their own begin()/complete() wrap does actually need anything more than speed and duplex (I didn't do a full check). Michal > Signed-off-by: Kai-Heng Feng > --- > net/ethtool/ioctl.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c > index 182bffbffa78..c768dbf45fc4 100644 > --- a/net/ethtool/ioctl.c > +++ b/net/ethtool/ioctl.c > @@ -423,13 +423,26 @@ struct ethtool_link_usettings { > int __ethtool_get_link_ksettings(struct net_device *dev, > struct ethtool_link_ksettings *link_ksettings) > { > + int rc; > + > ASSERT_RTNL(); > > if (!dev->ethtool_ops->get_link_ksettings) > return -EOPNOTSUPP; > > + if (dev->ethtool_ops->begin) { > + rc = dev->ethtool_ops->begin(dev); > + if (rc < 0) > + return rc; > + } > + > memset(link_ksettings, 0, sizeof(*link_ksettings)); > - return dev->ethtool_ops->get_link_ksettings(dev, link_ksettings); > + rc = dev->ethtool_ops->get_link_ksettings(dev, link_ksettings); > + > + if (dev->ethtool_ops->complete) > + dev->ethtool_ops->complete(dev); > + > + return rc; > } > EXPORT_SYMBOL(__ethtool_get_link_ksettings); > > -- > 2.17.1 >