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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 2E754C3279B for ; Fri, 6 Jul 2018 10:01:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D792624003 for ; Fri, 6 Jul 2018 10:01:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D792624003 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753839AbeGFKBg (ORCPT ); Fri, 6 Jul 2018 06:01:36 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:59504 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751517AbeGFKBe (ORCPT ); Fri, 6 Jul 2018 06:01:34 -0400 Received: from 79.184.254.38.ipv4.supernova.orange.pl (79.184.254.38) (HELO aspire.rjw.lan) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83) id e393566fd7189947; Fri, 6 Jul 2018 12:01:32 +0200 From: "Rafael J. Wysocki" To: Greg Kroah-Hartman Cc: Pingfan Liu , linux-kernel@vger.kernel.org, Grygorii Strashko , Christoph Hellwig , Bjorn Helgaas , Dave Young , linux-pci@vger.kernel.org, Lukas Wunner , Linux PM Subject: [PATCH] driver core: Drop devices_kset_move_last() call from really_probe() Date: Fri, 06 Jul 2018 12:00:06 +0200 Message-ID: <8816662.k3KXbdkA2e@aspire.rjw.lan> In-Reply-To: References: <1530600642-25090-1-git-send-email-kernelfans@gmail.com> <2108146.dv4EAOf6IP@aspire.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki The devices_kset_move_last() call in really_probe() is a mistake as it may cause parents to follow children in the devices_kset list which then causes system shutdown to fail. Namely, if a device has children before really_probe() is called for it (which is not uncommon), that call will cause it to be reordered after the children in the devices_kset list and the ordering of that list will not reflect the correct device shutdown order. Also it causes the devices_kset list to be constantly reordered until all drivers have been probed which is totally pointless overhead in the majority of cases. For that reason, revert the really_probe() modifications made by commit 52cdbdd49853. Fixes: 52cdbdd49853 (driver core: correct device's shutdown order) Link: https://lore.kernel.org/lkml/CAFgQCTt7VfqM=UyCnvNFxrSw8Z6cUtAi3HUwR4_xPAc03SgHjQ@mail.gmail.com/ Reported-by: Pingfan Liu Signed-off-by: Rafael J. Wysocki --- drivers/base/dd.c | 8 -------- 1 file changed, 8 deletions(-) Index: linux-pm/drivers/base/dd.c =================================================================== --- linux-pm.orig/drivers/base/dd.c +++ linux-pm/drivers/base/dd.c @@ -434,14 +434,6 @@ re_probe: goto probe_failed; } - /* - * Ensure devices are listed in devices_kset in correct order - * It's important to move Dev to the end of devices_kset before - * calling .probe, because it could be recursive and parent Dev - * should always go first - */ - devices_kset_move_last(dev); - if (dev->bus->probe) { ret = dev->bus->probe(dev); if (ret)