From patchwork Mon Sep 28 13:13:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mircea Caprioru X-Patchwork-Id: 11803831 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E5F96618 for ; Mon, 28 Sep 2020 13:14:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5A1521D7F for ; Mon, 28 Sep 2020 13:14:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726645AbgI1NOe (ORCPT ); Mon, 28 Sep 2020 09:14:34 -0400 Received: from mx0a-00128a01.pphosted.com ([148.163.135.77]:33402 "EHLO mx0a-00128a01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726772AbgI1NOZ (ORCPT ); Mon, 28 Sep 2020 09:14:25 -0400 Received: from pps.filterd (m0167089.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 08SD7OFb000957; Mon, 28 Sep 2020 09:14:12 -0400 Received: from nwd2mta3.analog.com ([137.71.173.56]) by mx0a-00128a01.pphosted.com with ESMTP id 33t2j4f823-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 28 Sep 2020 09:14:12 -0400 Received: from SCSQMBX11.ad.analog.com (scsqmbx11.ad.analog.com [10.77.17.10]) by nwd2mta3.analog.com (8.14.7/8.14.7) with ESMTP id 08SDEBG5065317 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=FAIL); Mon, 28 Sep 2020 09:14:11 -0400 Received: from SCSQCASHYB7.ad.analog.com (10.77.17.133) by SCSQMBX11.ad.analog.com (10.77.17.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1779.2; Mon, 28 Sep 2020 06:14:04 -0700 Received: from SCSQMBX10.ad.analog.com (10.77.17.5) by SCSQCASHYB7.ad.analog.com (10.77.17.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1779.2; Mon, 28 Sep 2020 06:14:04 -0700 Received: from zeus.spd.analog.com (10.66.68.11) by SCSQMBX10.ad.analog.com (10.77.17.5) with Microsoft SMTP Server id 15.1.1779.2 via Frontend Transport; Mon, 28 Sep 2020 06:14:04 -0700 Received: from localhost.localdomain ([10.48.65.12]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 08SDDuB8030926; Mon, 28 Sep 2020 09:14:06 -0400 From: Mircea Caprioru To: CC: , , , , , , Sergiu Cuciurean , Mircea Caprioru Subject: [PATCH 5/5] iio: adc: rockchip_saradc: Replace indio_dev->mlock with own device lock Date: Mon, 28 Sep 2020 16:13:33 +0300 Message-ID: <20200928131333.36646-5-mircea.caprioru@analog.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200928131333.36646-1-mircea.caprioru@analog.com> References: <20200928131333.36646-1-mircea.caprioru@analog.com> MIME-Version: 1.0 X-ADIRoutedOnPrem: True X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-28_11:2020-09-28,2020-09-28 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 suspectscore=0 priorityscore=1501 phishscore=0 spamscore=0 malwarescore=0 bulkscore=0 clxscore=1015 mlxlogscore=748 mlxscore=0 adultscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009280104 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Sergiu Cuciurean As part of the general cleanup of indio_dev->mlock, this change replaces it with a local lock on the device's state structure. This is part of a bigger cleanup. Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/ Signed-off-by: Sergiu Cuciurean Signed-off-by: Mircea Caprioru --- drivers/iio/adc/rockchip_saradc.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c index 1f3d7d639d37..80084c526cc6 100644 --- a/drivers/iio/adc/rockchip_saradc.c +++ b/drivers/iio/adc/rockchip_saradc.c @@ -53,6 +53,15 @@ struct rockchip_saradc { const struct rockchip_saradc_data *data; u16 last_val; const struct iio_chan_spec *last_chan; + /* + * Lock to protect the device state during a potential concurrent + * read access from userspace. Reading a raw value requires a sequence + * of register writes, then a wait for a completion callback, + * and finally a register read, during which userspace could issue + * another read request. This lock protects a read access from + * ocurring before another one has finished. + */ + struct mutex lock; }; static void rockchip_saradc_power_down(struct rockchip_saradc *info) @@ -92,17 +101,17 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_RAW: - mutex_lock(&indio_dev->mlock); + mutex_lock(&info->lock); ret = rockchip_saradc_conversion(info, chan); if (ret) { rockchip_saradc_power_down(info); - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&info->lock); return ret; } *val = info->last_val; - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&info->lock); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: ret = regulator_get_voltage(info->vref); @@ -254,7 +263,7 @@ static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p) int ret; int i, j = 0; - mutex_lock(&i_dev->mlock); + mutex_lock(&info->lock); for_each_set_bit(i, i_dev->active_scan_mask, i_dev->masklength) { const struct iio_chan_spec *chan = &i_dev->channels[i]; @@ -271,7 +280,7 @@ static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p) iio_push_to_buffers_with_timestamp(i_dev, &data, iio_get_time_ns(i_dev)); out: - mutex_unlock(&i_dev->mlock); + mutex_unlock(&info->lock); iio_trigger_notify_done(i_dev->trig); @@ -332,6 +341,8 @@ static int rockchip_saradc_probe(struct platform_device *pdev) info->reset = NULL; } + mutex_init(&info->lock); + init_completion(&info->completion); irq = platform_get_irq(pdev, 0);