From patchwork Tue Oct 4 13:48:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nuno Sa X-Patchwork-Id: 12998395 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6DFCFC43219 for ; Tue, 4 Oct 2022 13:49:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229825AbiJDNtn (ORCPT ); Tue, 4 Oct 2022 09:49:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229779AbiJDNtj (ORCPT ); Tue, 4 Oct 2022 09:49:39 -0400 Received: from mx0a-00128a01.pphosted.com (mx0a-00128a01.pphosted.com [148.163.135.77]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B4B32B255 for ; Tue, 4 Oct 2022 06:49:32 -0700 (PDT) Received: from pps.filterd (m0167089.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 294C9Ox8025012; Tue, 4 Oct 2022 09:48:33 -0400 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com (PPS) with ESMTPS id 3jxjf733g6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 04 Oct 2022 09:48:33 -0400 Received: from ASHBMBX9.ad.analog.com (ASHBMBX9.ad.analog.com [10.64.17.10]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 294DmWpP001531 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 4 Oct 2022 09:48:32 -0400 Received: from ASHBMBX9.ad.analog.com (10.64.17.10) by ASHBMBX9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.14; Tue, 4 Oct 2022 09:48:31 -0400 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server id 15.2.986.14 via Frontend Transport; Tue, 4 Oct 2022 09:48:31 -0400 Received: from nsa.ad.analog.com ([10.44.3.52]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 294DlkVY032663; Tue, 4 Oct 2022 09:48:19 -0400 From: =?utf-8?q?Nuno_S=C3=A1?= To: , , , , CC: Heiko Stuebner , Martin Blumenstingl , Neil Armstrong , Shawn Guo , Lars-Peter Clausen , Jyoti Bhayana , Hans de Goede , Andriy Tryshnivskyy , Pengutronix Kernel Team , Miquel Raynal , Cixi Geng , Baolin Wang , Ciprian Regus , Fabio Estevam , =?utf-8?q?Nuno_S=C3=A1?= , Sascha Hauer , Alexandru Ardelean , Florian Boor , Michael Hennerich , Orson Zhai , Chen-Yu Tsai , Chunyan Zhang , Vladimir Zapolskiy , Andy Shevchenko , Jerome Brunet , Haibo Chen , Kevin Hilman , Jonathan Cameron Subject: [PATCH v2 01/16] iio: adc: ad799x: do not use internal iio_dev lock Date: Tue, 4 Oct 2022 15:48:54 +0200 Message-ID: <20221004134909.1692021-2-nuno.sa@analog.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221004134909.1692021-1-nuno.sa@analog.com> References: <20221004134909.1692021-1-nuno.sa@analog.com> MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: SS5WqGEP61nJ1tXif6qOZQ3eX25vwLYQ X-Proofpoint-ORIG-GUID: SS5WqGEP61nJ1tXif6qOZQ3eX25vwLYQ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-10-04_06,2022-09-29_03,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 malwarescore=0 bulkscore=0 mlxscore=0 priorityscore=1501 spamscore=0 adultscore=0 impostorscore=0 lowpriorityscore=0 phishscore=0 suspectscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2210040089 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org 'mlock' was being grabbed when setting the device frequency. In order to not introduce any functional change a new lock is added. With that in mind, the lock also needs to be grabbed in the places where 'mlock' is since it was also being used to protect st->config against the current device state. On the other places the lock was being used, we can just drop it since we are only doing one i2c bus read/write which is already safe. While at it, properly include "mutex.h" for mutex related APIs. Signed-off-by: Nuno Sá --- drivers/iio/adc/ad799x.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c index 262bd7665b33..44f7a80a0749 100644 --- a/drivers/iio/adc/ad799x.c +++ b/drivers/iio/adc/ad799x.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -125,6 +126,8 @@ struct ad799x_state { const struct ad799x_chip_config *chip_config; struct regulator *reg; struct regulator *vref; + /* lock to protect against multiple access to the device */ + struct mutex lock; unsigned id; u16 config; @@ -290,7 +293,9 @@ static int ad799x_read_raw(struct iio_dev *indio_dev, ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; + mutex_lock(&st->lock); ret = ad799x_scan_direct(st, chan->scan_index); + mutex_unlock(&st->lock); iio_device_release_direct_mode(indio_dev); if (ret < 0) @@ -351,7 +356,8 @@ static ssize_t ad799x_write_frequency(struct device *dev, if (ret) return ret; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); + ret = i2c_smbus_read_byte_data(st->client, AD7998_CYCLE_TMR_REG); if (ret < 0) goto error_ret_mutex; @@ -373,7 +379,7 @@ static ssize_t ad799x_write_frequency(struct device *dev, ret = len; error_ret_mutex: - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return ret; } @@ -407,6 +413,8 @@ static int ad799x_write_event_config(struct iio_dev *indio_dev, if (ret) return ret; + mutex_lock(&st->lock); + if (state) st->config |= BIT(chan->scan_index) << AD799X_CHANNEL_SHIFT; else @@ -418,6 +426,7 @@ static int ad799x_write_event_config(struct iio_dev *indio_dev, st->config &= ~AD7998_ALERT_EN; ret = ad799x_write_config(st, st->config); + mutex_unlock(&st->lock); iio_device_release_direct_mode(indio_dev); return ret; } @@ -454,11 +463,9 @@ static int ad799x_write_event_value(struct iio_dev *indio_dev, if (val < 0 || val > GENMASK(chan->scan_type.realbits - 1, 0)) return -EINVAL; - mutex_lock(&indio_dev->mlock); ret = i2c_smbus_write_word_swapped(st->client, ad799x_threshold_reg(chan, dir, info), val << chan->scan_type.shift); - mutex_unlock(&indio_dev->mlock); return ret; } @@ -473,10 +480,8 @@ static int ad799x_read_event_value(struct iio_dev *indio_dev, int ret; struct ad799x_state *st = iio_priv(indio_dev); - mutex_lock(&indio_dev->mlock); ret = i2c_smbus_read_word_swapped(st->client, ad799x_threshold_reg(chan, dir, info)); - mutex_unlock(&indio_dev->mlock); if (ret < 0) return ret; *val = (ret >> chan->scan_type.shift) & @@ -863,6 +868,9 @@ static int ad799x_probe(struct i2c_client *client, if (ret) goto error_cleanup_ring; } + + mutex_init(&st->lock); + ret = iio_device_register(indio_dev); if (ret) goto error_cleanup_ring;