From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51034 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754511AbcEBSWS (ORCPT ); Mon, 2 May 2016 14:22:18 -0400 Subject: Patch "regulator: core: Fix nested locking of supplies" has been added to the 4.4-stable tree To: treding@nvidia.com, arnd@arndb.de, broonie@kernel.org, gregkh@linuxfoundation.org, linux@roeck-us.net Cc: , From: Date: Mon, 02 May 2016 11:22:17 -0700 Message-ID: <1462213337143126@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled regulator: core: Fix nested locking of supplies to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: regulator-core-fix-nested-locking-of-supplies.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 70a7fb80e85ae7f78f8e90cec3fbd862ea6a4d4b Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 2 Dec 2015 16:54:50 +0100 Subject: regulator: core: Fix nested locking of supplies From: Thierry Reding commit 70a7fb80e85ae7f78f8e90cec3fbd862ea6a4d4b upstream. Commit fa731ac7ea04 ("regulator: core: avoid unused variable warning") introduced a subtle change in how supplies are locked. Where previously code was always locking the regulator of the current iteration, the new implementation only locks the regulator if it has a supply. For any given power tree that means that the root will never get locked. On the other hand the regulator_unlock_supply() will still release all the locks, which in turn causes the lock debugging code to warn about a mutex being unlocked which wasn't locked. Cc: Mark Brown Cc: Arnd Bergmann Fixes: fa731ac7ea04 ("regulator: core: avoid unused variable warning") Signed-off-by: Thierry Reding Signed-off-by: Mark Brown Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/regulator/core.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -132,6 +132,14 @@ static bool have_full_constraints(void) return has_full_constraints || of_have_populated_dt(); } +static inline struct regulator_dev *rdev_get_supply(struct regulator_dev *rdev) +{ + if (rdev && rdev->supply) + return rdev->supply->rdev; + + return NULL; +} + /** * regulator_lock_supply - lock a regulator and its supplies * @rdev: regulator source @@ -140,8 +148,7 @@ static void regulator_lock_supply(struct { int i; - mutex_lock(&rdev->mutex); - for (i = 1; rdev; rdev = rdev->supply->rdev, i++) + for (i = 0; rdev; rdev = rdev_get_supply(rdev), i++) mutex_lock_nested(&rdev->mutex, i); } Patches currently in stable-queue which might be from treding@nvidia.com are queue-4.4/regulator-core-fix-nested-locking-of-supplies.patch queue-4.4/revert-regulator-core-fix-nested-locking-of-supplies.patch