From patchwork Sat Oct 17 00:40:58 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Richardson X-Patchwork-Id: 531594 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id CBBD614110C for ; Sat, 17 Oct 2015 11:41:00 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752570AbbJQAkP (ORCPT ); Fri, 16 Oct 2015 20:40:15 -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" Received: from irvexchcas08.broadcom.com (HELO IRVEXCHCAS08.corp.ad.broadcom.com) ([10.9.208.57]) by mail-gw1-out.broadcom.com with ESMTP; 16 Oct 2015 19:34:09 -0700 Received: from IRVEXCHSMTP1.corp.ad.broadcom.com (10.9.207.51) by IRVEXCHCAS08.corp.ad.broadcom.com (10.9.208.57) with Microsoft SMTP Server (TLS) id 14.3.235.1; Fri, 16 Oct 2015 17:40:12 -0700 Received: from mail-irva-13.broadcom.com (10.10.10.20) by IRVEXCHSMTP1.corp.ad.broadcom.com (10.9.207.51) with Microsoft SMTP Server id 14.3.235.1; Fri, 16 Oct 2015 17:40:12 -0700 Received: from lbrmn-lnxub108.corp.ad.broadcom.com (unknown [10.136.4.151]) by mail-irva-13.broadcom.com (Postfix) with ESMTP id 5F16041059; Fri, 16 Oct 2015 17:37:09 -0700 (PDT) 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 Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@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;