From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752739AbbJQAlB (ORCPT ); Fri, 16 Oct 2015 20:41:01 -0400 Received: from mail-gw1-out.broadcom.com ([216.31.210.62]:50274 "EHLO mail-gw1-out.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752492AbbJQAkN (ORCPT ); Fri, 16 Oct 2015 20:40:13 -0400 X-IronPort-AV: E=Sophos;i="5.17,691,1437462000"; d="scan'208";a="77965752" 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 v10 1/1] pwm: core: Set enable state properly on failed call to enable Date: Fri, 16 Oct 2015 17:40:58 -0700 Message-ID: <1445042458-30725-2-git-send-email-jonathar@broadcom.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1445042458-30725-1-git-send-email-jonathar@broadcom.com> References: <1445042458-30725-1-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 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 | 33 ++++++++++++++++++++++++++------- include/linux/pwm.h | 2 ++ 2 files changed, 28 insertions(+), 7 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 3f9df3e..b8f6c30 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -269,6 +269,7 @@ 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); } @@ -473,16 +474,22 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) if (!pwm->chip->ops->set_polarity) return -ENOSYS; - if (pwm_is_enabled(pwm)) - return -EBUSY; + mutex_lock(&pwm->lock); + + if (pwm_is_enabled(pwm)) { + err = -EBUSY; + goto unlock; + } err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); if (err) - return err; + goto unlock; pwm->polarity = polarity; - return 0; +unlock: + mutex_unlock(&pwm->lock); + return err; } EXPORT_SYMBOL_GPL(pwm_set_polarity); @@ -494,10 +501,22 @@ 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; + + 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 pwm ? 0 : -EINVAL; + return err; } EXPORT_SYMBOL_GPL(pwm_enable); diff --git a/include/linux/pwm.h b/include/linux/pwm.h index d681f68..dee7d65 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -3,6 +3,7 @@ #include #include +#include struct pwm_device; struct seq_file; @@ -98,6 +99,7 @@ struct pwm_device { unsigned int pwm; struct pwm_chip *chip; void *chip_data; + struct mutex lock; unsigned int period; unsigned int duty_cycle; -- 1.9.1