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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 234B1C2D0A8 for ; Wed, 23 Sep 2020 20:15:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C53B1206DB for ; Wed, 23 Sep 2020 20:15:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726796AbgIWUPe (ORCPT ); Wed, 23 Sep 2020 16:15:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726476AbgIWUPc (ORCPT ); Wed, 23 Sep 2020 16:15:32 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3691C0613CE; Wed, 23 Sep 2020 13:15:32 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 209A111E3E4CA; Wed, 23 Sep 2020 12:58:43 -0700 (PDT) Date: Wed, 23 Sep 2020 13:15:29 -0700 (PDT) Message-Id: <20200923.131529.637266321442993059.davem@davemloft.net> To: hkallweit1@gmail.com Cc: saeed@kernel.org, geert+renesas@glider.be, f.fainelli@gmail.com, andrew@lunn.ch, kuba@kernel.org, gaku.inami.xh@renesas.com, yoshihiro.shimoda.uh@renesas.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Revert "net: linkwatch: add check for netdevice being present to linkwatch_do_dev" From: David Miller In-Reply-To: <14f41724-ce45-c2c0-a49c-1e379dba0cb5@gmail.com> References: <3d9176a6-c93e-481c-5877-786f5e6aaef8@gmail.com> <28da797abe486e783547c60a25db44be0c030d86.camel@kernel.org> <14f41724-ce45-c2c0-a49c-1e379dba0cb5@gmail.com> X-Mailer: Mew version 6.8 on Emacs 27.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [2620:137:e000::1:9]); Wed, 23 Sep 2020 12:58:43 -0700 (PDT) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Heiner Kallweit Date: Wed, 23 Sep 2020 21:58:59 +0200 > On 23.09.2020 20:35, Saeed Mahameed wrote: >> Why would a driver detach the device on ndo_stop() ? >> seems like this is the bug you need to be chasing .. >> which driver is doing this ? >> > Some drivers set the device to PCI D3hot at the end of ndo_stop() > to save power (using e.g. Runtime PM). Marking the device as detached > makes clear to to the net core that the device isn't accessible any > longer. That being the case, the problem is that IFF_UP+!present is not a valid netdev state. Is it simply the issue that, upon resume, IFF_UP is marked true before the device is brought out from D3hot state and thus marked as present again?