From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751468AbdJRXqI (ORCPT ); Wed, 18 Oct 2017 19:46:08 -0400 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:41816 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750829AbdJRXqH (ORCPT ); Wed, 18 Oct 2017 19:46:07 -0400 From: "Rafael J. Wysocki" To: Jeffy Chen Cc: linux-kernel@vger.kernel.org, seanpaul@chromium.irg, briannorris@chromium.org, heiko@sntech.de, gregkh@linuxfoundation.org, dmitry.torokhov@gmail.com, dianders@chromium.org, tfiga@chromium.org, broonie@kernel.org, thierry.reding@gmail.com Subject: Re: [PATCH] driver core: Move device_links_purge() after bus_remove_device() Date: Thu, 19 Oct 2017 01:36:27 +0200 Message-ID: <2591080.ki3098E8CB@aspire.rjw.lan> In-Reply-To: <20171018112839.31985-1-jeffy.chen@rock-chips.com> References: <20171018112839.31985-1-jeffy.chen@rock-chips.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, October 18, 2017 1:28:38 PM CEST Jeffy Chen wrote: > Currently we are unbinding device link consumers when detaching the > supplier. So we need to make sure the detaching happens before purging > the supplier's device links. > > Move device_links_purge() after bus_remove_device() in device_del() > for that. > > Signed-off-by: Jeffy Chen Yes, we can do that, but the changelog is somewhat hard to understand IMO. Why don't you write something like the following: "The current ordering of code in device_del() triggers a WARN_ON() in device_links_purge(), because of an unexpected link status. The device_links_unbind_consumers() call in device_release_driver() has to take place before device_links_purge() for the status of all links to be correct, so move the device_links_purge() call in device_del() after the invocation of bus_remove_device() which calls device_release_driver()." > --- > > drivers/base/core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 12ebd055724c..2e683cdf4a08 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -1958,7 +1958,6 @@ void device_del(struct device *dev) > blocking_notifier_call_chain(&dev->bus->p->bus_notifier, > BUS_NOTIFY_DEL_DEVICE, dev); > > - device_links_purge(dev); > dpm_sysfs_remove(dev); > if (parent) > klist_del(&dev->p->knode_parent); > @@ -1986,6 +1985,7 @@ void device_del(struct device *dev) > device_pm_remove(dev); > driver_deferred_probe_del(dev); > device_remove_properties(dev); > + device_links_purge(dev); > > /* Notify the platform of the removal, in case they > * need to do anything... >