Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755185AbbB0Tl0 (ORCPT ); Fri, 27 Feb 2015 14:41:26 -0500 Received: from mail-ig0-f170.google.com ([209.85.213.170]:43416 "EHLO mail-ig0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753539AbbB0TlY (ORCPT ); Fri, 27 Feb 2015 14:41:24 -0500 From: Doug Anderson To: Mark Brown Cc: milo.kim@ti.com, axel.lin@ingics.com, Dmitry Torokhov , olof@lixom.net, javier.martinez@collabora.co.uk, Paul Stewart , Doug Anderson , , lgirdwood@gmail.com, linux-kernel@vger.kernel.org Subject: [PATCH] regulator: core: Fix enable GPIO reference counting Date: Fri, 27 Feb 2015 11:41:03 -0800 Message-Id: <1425066064-18920-1-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 2.2.0.rc0.207.ga3a616c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2279 Lines: 66 It is possible for _regulator_do_enable() to be called for an already-enabled rdev, like in regulator_suspend_finish(). If we were using an enable pin (rdev->ena_pin is set) then we'd end up incrementing the reference count in regulator_ena_gpio_ctrl() over and over again without a decrement. That prevented the GPIO from going to the "off" state even after all users were disabled. Fix this by avoiding the call to regulator_ena_gpio_ctrl() when it's not needed. Signed-off-by: Doug Anderson Fixes: 967cfb18c0e3 ("regulator: core: manage enable GPIO list") --- FYI: this was developed and tested against a 3.14 kernel with backports; I've done basic boot testing against upstream and sanity checked the code but haven't done as extensive testing there. drivers/regulator/core.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index b899947..9daccbb 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1839,10 +1839,12 @@ static int _regulator_do_enable(struct regulator_dev *rdev) } if (rdev->ena_pin) { - ret = regulator_ena_gpio_ctrl(rdev, true); - if (ret < 0) - return ret; - rdev->ena_gpio_state = 1; + if (!rdev->ena_gpio_state) { + ret = regulator_ena_gpio_ctrl(rdev, true); + if (ret < 0) + return ret; + rdev->ena_gpio_state = 1; + } } else if (rdev->desc->ops->enable) { ret = rdev->desc->ops->enable(rdev); if (ret < 0) @@ -1939,10 +1941,12 @@ static int _regulator_do_disable(struct regulator_dev *rdev) trace_regulator_disable(rdev_get_name(rdev)); if (rdev->ena_pin) { - ret = regulator_ena_gpio_ctrl(rdev, false); - if (ret < 0) - return ret; - rdev->ena_gpio_state = 0; + if (rdev->ena_gpio_state) { + ret = regulator_ena_gpio_ctrl(rdev, false); + if (ret < 0) + return ret; + rdev->ena_gpio_state = 0; + } } else if (rdev->desc->ops->disable) { ret = rdev->desc->ops->disable(rdev); -- 2.2.0.rc0.207.ga3a616c -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/