From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758731AbcIHV0g (ORCPT ); Thu, 8 Sep 2016 17:26:36 -0400 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:50415 "HELO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1758571AbcIHVZy (ORCPT ); Thu, 8 Sep 2016 17:25:54 -0400 From: "Rafael J. Wysocki" To: Linux PM list Cc: Greg Kroah-Hartman , Alan Stern , Linux Kernel Mailing List , Tomeu Vizoso , Mark Brown , Marek Szyprowski , Lukas Wunner , Kevin Hilman , Ulf Hansson , "Luis R. Rodriguez" Subject: [RFC/RFT][PATCH v2 1/7] driver core: Add a wrapper around __device_release_driver() Date: Thu, 08 Sep 2016 23:26:47 +0200 Message-ID: <7766666.xAo06mNC7J@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.8.0-rc2+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <27296716.H9VWo8ShOm@vostro.rjw.lan> References: <27296716.H9VWo8ShOm@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. A subsequent change will make use of it. Signed-off-by: Rafael J. Wysocki --- drivers/base/dd.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 16688f50729c..d9e76e9205c7 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -796,6 +796,22 @@ static void __device_release_driver(struct device *dev) } } +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. @@ -810,9 +826,7 @@ void device_release_driver(struct device *dev) * 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); @@ -837,15 +851,7 @@ void driver_detach(struct device_driver *drv) 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); } }