From patchwork Tue Sep 20 11:28:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nuno Sa X-Patchwork-Id: 12981969 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D6B8FECAAD8 for ; Tue, 20 Sep 2022 11:30:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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Tue, 20 Sep 2022 07:27:53 -0400 Received: from ASHBMBX8.ad.analog.com (ASHBMBX8.ad.analog.com [10.64.17.5]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 28KBRpQO060606 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 20 Sep 2022 07:27:51 -0400 Received: from ASHBMBX9.ad.analog.com (10.64.17.10) by ASHBMBX8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.14; Tue, 20 Sep 2022 07:27:50 -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, 20 Sep 2022 07:27:50 -0400 Received: from nsa.ad.analog.com ([10.44.3.57]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 28KBR4UO021723; Tue, 20 Sep 2022 07:27:41 -0400 From: =?utf-8?q?Nuno_S=C3=A1?= To: , , , , CC: Chunyan Zhang , Michael Hennerich , Martin Blumenstingl , Sascha Hauer , Cixi Geng , Kevin Hilman , Vladimir Zapolskiy , Pengutronix Kernel Team , Alexandru Ardelean , Fabio Estevam , Andriy Tryshnivskyy , Haibo Chen , Shawn Guo , Hans de Goede , Miquel Raynal , Jerome Brunet , Heiko Stuebner , Florian Boor , Ciprian Regus , Lars-Peter Clausen , Andy Shevchenko , Jonathan Cameron , Neil Armstrong , Baolin Wang , Jyoti Bhayana , =?utf-8?q?Nuno_S=C3=A1?= , Chen-Yu Tsai , Orson Zhai Subject: [PATCH 02/15] iio: adc: ad799x: do not use internal iio_dev lock Date: Tue, 20 Sep 2022 13:28:08 +0200 Message-ID: <20220920112821.975359-3-nuno.sa@analog.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220920112821.975359-1-nuno.sa@analog.com> References: <20220920112821.975359-1-nuno.sa@analog.com> MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-ORIG-GUID: hJCkUkms2Kofut7eTZiTrqI_koL0phqg X-Proofpoint-GUID: hJCkUkms2Kofut7eTZiTrqI_koL0phqg 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=2022-09-20_03,2022-09-16_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 adultscore=0 impostorscore=0 phishscore=0 priorityscore=1501 suspectscore=0 spamscore=0 malwarescore=0 mlxscore=0 mlxlogscore=999 bulkscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2209200068 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220920_042807_956138_2F89AD6F X-CRM114-Status: GOOD ( 17.17 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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. 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. Signed-off-by: Nuno Sá --- drivers/iio/adc/ad799x.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c index 262bd7665b33..838ba8e77de1 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) & @@ -785,6 +790,7 @@ static int ad799x_probe(struct i2c_client *client, return -ENOMEM; st = iio_priv(indio_dev); + mutex_init(&st->lock); /* this is only used for device removal purposes */ i2c_set_clientdata(client, indio_dev);