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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 45AD0C3279B for ; Tue, 10 Jul 2018 13:00:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 098E920877 for ; Tue, 10 Jul 2018 13:00:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 098E920877 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S933344AbeGJNAB (ORCPT ); Tue, 10 Jul 2018 09:00:01 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:59238 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752652AbeGJM77 (ORCPT ); Tue, 10 Jul 2018 08:59:59 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 960EECFC; Tue, 10 Jul 2018 12:59:58 +0000 (UTC) Date: Tue, 10 Jul 2018 14:59:56 +0200 From: Greg Kroah-Hartman To: "Rafael J. Wysocki" 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 , Kishon Vijay Abraham I Subject: Re: [PATCH v2] driver core: Partially revert "driver core: correct device's shutdown order" Message-ID: <20180710125956.GA25343@kroah.com> References: <1530600642-25090-1-git-send-email-kernelfans@gmail.com> <8816662.k3KXbdkA2e@aspire.rjw.lan> <2927655.Y1qg3UnIrE@aspire.rjw.lan> <5284251.Resgjlja2Q@aspire.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5284251.Resgjlja2Q@aspire.rjw.lan> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 10, 2018 at 02:51:33PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Commit 52cdbdd49853 (driver core: correct device's shutdown order) > introduced a regression by breaking device shutdown on some systems. > > Namely, the devices_kset_move_last() call in really_probe() added by > that commit is a mistake as it may cause parents to follow children > in the devices_kset list which then causes shutdown to fail. For > example, 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 any more. > > 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 and it only covered an issue > with system shutdown, while system-wide suspend/resume potentially > had the same issue on the affected platforms (which was not covered). > > Moreover, the shutdown issue originally addressed by the change in > really_probe() made by commit 52cdbdd49853 is not present in 4.18-rc > any more, since dra7 started to use the sdhci-omap driver which > doesn't disable any regulators during shutdown, so the really_probe() > part of commit 52cdbdd49853 can be safely reverted. [The original > issue was related to the omap_hsmmc driver used by dra7 previously.] > > For the above reasons, revert the really_probe() modifications made > by commit 52cdbdd49853. > > The other code changes made by commit 52cdbdd49853 are useful and > they need not be reverted. > > 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 > Tested-by: Pingfan Liu > Reviewed-by: Kishon Vijay Abraham I > Signed-off-by: Rafael J. Wysocki > --- > > -> v2: Added information from Kishon on the fact that it should be safe > to revert the really_probe() modifications added by the > problematic commit. Also added the Reviewed-by tag from Kishon. Looks good to me, want me to queue it up in my tree, or are you going to send it on to Linus? And shouldn't this have a stable tag as well? thanks, greg k-h