Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756008AbbFOVSG (ORCPT ); Mon, 15 Jun 2015 17:18:06 -0400 Received: from mail-gw3-out.broadcom.com ([216.31.210.64]:41577 "EHLO mail-gw3-out.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752087AbbFOVRf (ORCPT ); Mon, 15 Jun 2015 17:17:35 -0400 X-IronPort-AV: E=Sophos;i="5.13,621,1427785200"; d="scan'208";a="67341701" From: Jonathan Richardson To: Tim Kryger , Dmitry Torokhov , Anatol Pomazau , Arun Ramamurthy , Thierry Reding CC: Scott Branden , Jonathan Richardson , bcm-kernel-feedback-list , , Subject: [PATCH v9 2/2] pwm: core: Set enable state properly on failed call to enable Date: Mon, 15 Jun 2015 14:21:02 -0700 Message-ID: <1434403262-24198-3-git-send-email-jonathar@broadcom.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1434403262-24198-1-git-send-email-jonathar@broadcom.com> References: <1434403262-24198-1-git-send-email-jonathar@broadcom.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2238 Lines: 79 The pwm_enable function didn't clear the enabled bit if a call to a clients enable function returned an error. The result was that the state of the pwm core was wrong. Clearing the bit when enable returns an error ensures the state is properly set. Tested-by: Jonathan Richardson Reviewed-by: Dmitry Torokhov Signed-off-by: Jonathan Richardson --- drivers/pwm/core.c | 19 ++++++++++++++++--- include/linux/pwm.h | 2 ++ 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 76b0386..c255267 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -263,6 +263,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, pwm->pwm = chip->base + i; pwm->hwpwm = i; pwm->polarity = polarity; + mutex_init(&pwm->lock); radix_tree_insert(&pwm_tree, pwm->pwm, pwm); } @@ -474,10 +475,22 @@ EXPORT_SYMBOL_GPL(pwm_set_polarity); */ int pwm_enable(struct pwm_device *pwm) { - if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) - return pwm->chip->ops->enable(pwm->chip, pwm); + int err = 0; - return pwm ? 0 : -EINVAL; + if (!pwm) + return -EINVAL; + + mutex_lock(&pwm->lock); + + if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) { + err = pwm->chip->ops->enable(pwm->chip, pwm); + if (err) + clear_bit(PWMF_ENABLED, &pwm->flags); + } + + mutex_unlock(&pwm->lock); + + return err; } EXPORT_SYMBOL_GPL(pwm_enable); diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 9daf0ef..50f28e6 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -3,6 +3,7 @@ #include #include +#include struct pwm_device; struct seq_file; @@ -86,6 +87,7 @@ struct pwm_device { unsigned int pwm; struct pwm_chip *chip; void *chip_data; + struct mutex lock; unsigned int period; /* in nanoseconds */ unsigned int duty_cycle; /* in nanoseconds */ -- 1.7.9.5 -- 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/