From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754963AbbK0RIS (ORCPT ); Fri, 27 Nov 2015 12:08:18 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:51602 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754597AbbK0RIR (ORCPT ); Fri, 27 Nov 2015 12:08:17 -0500 From: Mark Brown To: Geert Uytterhoeven , Arnd Bergmann , Mark Brown Cc: linux-kernel@vger.kernel.org In-Reply-To: <6486349.NfasOOYIHJ@wuerfel> Message-Id: Date: Fri, 27 Nov 2015 17:07:56 +0000 X-SA-Exim-Connect-IP: 94.175.94.161 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Applied "regulator: core: fix regulator_lock_supply regression" to the regulator tree X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The patch regulator: core: fix regulator_lock_supply regression has been applied to the regulator tree at git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >>From bb41897e38c53458a88b271f2fbcd905ee1f9584 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 27 Nov 2015 14:46:41 +0100 Subject: [PATCH] regulator: core: fix regulator_lock_supply regression 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 --- drivers/regulator/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index c70017d5f74b..daffff83ced2 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -140,7 +140,8 @@ static void regulator_lock_supply(struct regulator_dev *rdev) { 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); } -- 2.6.2