From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755868AbcANB5f (ORCPT ); Wed, 13 Jan 2016 20:57:35 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:59520 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755731AbcANB4q (ORCPT ); Wed, 13 Jan 2016 20:56:46 -0500 From: "Rafael J. Wysocki" To: Linux PM list Cc: Greg Kroah-Hartman , Linux Kernel Mailing List , Alan Stern , Grant Likely , Mark Brown , Rob Herring , Tomeu Vizoso , Thierry Reding , Dmitry Torokhov , Geert Uytterhoeven , Michael Turquette Subject: [RFC][PATCH 1/5] driver core: Add a wrapper around __device_release_driver() Date: Thu, 14 Jan 2016 02:53:28 +0100 Message-ID: <3655139.ja2psWCAU6@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.4.0; KDE/4.11.5; x86_64; ; ) In-Reply-To: <2576341.476ZsjkPgF@vostro.rjw.lan> References: <1623682.7KVblAB3KQ@vostro.rjw.lan> <2576341.476ZsjkPgF@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki Add an internal wrapper around __device_release_driver() that will acquire device locks and do the necessary checks before calling it. The next patch will make use of it. Signed-off-by: Rafael J. Wysocki --- drivers/base/dd.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) Index: linux-pm/drivers/base/dd.c =================================================================== --- linux-pm.orig/drivers/base/dd.c +++ linux-pm/drivers/base/dd.c @@ -776,6 +776,22 @@ static void __device_release_driver(stru } } +static void device_release_driver_internal(struct device *dev, + struct device_driver *drv, + struct device *parent) +{ + if (parent) + device_lock(parent); + + device_lock(dev); + if (!drv || drv == dev->driver) + __device_release_driver(dev); + + device_unlock(dev); + if (parent) + device_unlock(parent); +} + /** * device_release_driver - manually detach device from driver. * @dev: device. @@ -790,9 +806,7 @@ void device_release_driver(struct device * within their ->remove callback for the same device, they * will deadlock right here. */ - device_lock(dev); - __device_release_driver(dev); - device_unlock(dev); + device_release_driver_internal(dev, NULL, NULL); } EXPORT_SYMBOL_GPL(device_release_driver); @@ -817,15 +831,7 @@ void driver_detach(struct device_driver dev = dev_prv->device; get_device(dev); spin_unlock(&drv->p->klist_devices.k_lock); - - if (dev->parent) /* Needed for USB */ - device_lock(dev->parent); - device_lock(dev); - if (dev->driver == drv) - __device_release_driver(dev); - device_unlock(dev); - if (dev->parent) - device_unlock(dev->parent); + device_release_driver_internal(dev, drv, dev->parent); put_device(dev); } }