Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759683AbcDJS64 (ORCPT ); Sun, 10 Apr 2016 14:58:56 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:53080 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757206AbcDJS6m (ORCPT ); Sun, 10 Apr 2016 14:58:42 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Brown , Arnd Bergmann , Thierry Reding Subject: [PATCH 4.4 003/210] regulator: core: Fix nested locking of supplies Date: Sun, 10 Apr 2016 11:33:44 -0700 Message-Id: <20160410183526.771629440@linuxfoundation.org> X-Mailer: git-send-email 2.8.0 In-Reply-To: <20160410183526.651820045@linuxfoundation.org> References: <20160410183526.651820045@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1836 Lines: 56 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ 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: Fixes: fa731ac7ea04 ("regulator: core: avoid unused variable warning") Signed-off-by: Thierry Reding Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/regulator/core.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- 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 @@ -140,7 +148,7 @@ static void regulator_lock_supply(struct { int i; - for (i = 0; rdev->supply; rdev = rdev->supply->rdev, i++) + for (i = 0; rdev->supply; rdev = rdev_get_supply(rdev), i++) mutex_lock_nested(&rdev->mutex, i); }