From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51040 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754511AbcEBSWU (ORCPT ); Mon, 2 May 2016 14:22:20 -0400 Subject: Patch "regulator: core: fix regulator_lock_supply regression" has been added to the 4.4-stable tree To: arnd@arndb.de, broonie@kernel.org, geert@linux-m68k.org, gregkh@linuxfoundation.org, linux@roeck-us.net Cc: , From: Date: Mon, 02 May 2016 11:22:19 -0700 Message-ID: <1462213339187191@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 regulator_lock_supply regression 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-regulator_lock_supply-regression.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 bb41897e38c53458a88b271f2fbcd905ee1f9584 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 27 Nov 2015 14:46:41 +0100 Subject: regulator: core: fix regulator_lock_supply regression From: Arnd Bergmann commit bb41897e38c53458a88b271f2fbcd905ee1f9584 upstream. As noticed by Geert Uytterhoeven, my patch to avoid a harmless build warning in regulator_lock_supply() was total crap and introduced a real bug: > [ BUG: bad unlock balance detected! ] > kworker/u4:0/6 is trying to release lock (&rdev->mutex) at: > [] regulator_set_voltage+0x38/0x50 we still lock the regulator supplies, but not the actual regulators, so we are missing a lock, and the unlock is unbalanced. This rectifies it by first locking the regulator device itself before using the same loop as before to lock its supplies. Reported-by: Geert Uytterhoeven Signed-off-by: Arnd Bergmann Fixes: 716fec9d1965 ("[SUBMITTED] regulator: core: avoid unused variable warning") Signed-off-by: Mark Brown Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/regulator/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -140,7 +140,8 @@ static void regulator_lock_supply(struct { int i; - for (i = 0; rdev->supply; rdev = rdev->supply->rdev, i++) + mutex_lock(&rdev->mutex); + for (i = 1; rdev->supply; rdev = rdev->supply->rdev, i++) mutex_lock_nested(&rdev->mutex, i); } Patches currently in stable-queue which might be from arnd@arndb.de are queue-4.4/xen-kconfig-don-t-select-input_xen_kbddev_frontend.patch queue-4.4/asm-generic-futex-re-enable-preemption-in-futex_atomic_cmpxchg_inatomic.patch queue-4.4/regulator-core-fix-nested-locking-of-supplies.patch queue-4.4/regulator-core-fix-regulator_lock_supply-regression.patch queue-4.4/asoc-s3c24xx-use-const-snd_soc_component_driver-pointer.patch queue-4.4/revert-regulator-core-fix-nested-locking-of-supplies.patch