From patchwork Mon Feb 7 14:38:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 12737350 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 70000C433FE for ; Mon, 7 Feb 2022 14:59:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344620AbiBGO5C (ORCPT ); Mon, 7 Feb 2022 09:57:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243779AbiBGOiw (ORCPT ); Mon, 7 Feb 2022 09:38:52 -0500 Received: from relay11.mail.gandi.net (relay11.mail.gandi.net [IPv6:2001:4b98:dc4:8::231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A835C0401C3 for ; Mon, 7 Feb 2022 06:38:51 -0800 (PST) Received: (Authenticated sender: miquel.raynal@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 3AD4B100003; Mon, 7 Feb 2022 14:38:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1644244728; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D2L9sYqgzV4OcJCaeHyREjZc/sH2+iqdEfNzi+Hyc/4=; b=RKVMlMZI16xwTZjLBjz/F5iMkEW6aiX8J3aMHzd/s7Oywu0uJ36I8xpqM1t1KnXY2sYvHA u7KluXVM0/LiDo1MrgUWHNuwtbribm03sauac0cdx1uhoF57eTbRhXM1V44hdTT6TTE1Gf wOKazGhzypzJYx8emP2p2h9vc8TL87USSZhwoLzA0cGLvGj9eqQQZuiLIz4JihM2ziKDSh oqHqprP7aJSRFjLN4k8nysFWz497OGiSeYO/rEcwqIplBmstwNH0GxLiS1o2jCFX6vNR4I d6Fai/9R478Qhg30HYXkQZ18BQT8fQueuelRfZ6e+hTmgE/LrmtZwUUtVVlJUQ== From: Miquel Raynal To: linux-iio@vger.kernel.org, Jonathan Cameron , Lars-Peter Clausen Cc: Thomas Petazzoni , Alexandru Ardelean , Miquel Raynal , Denis Ciocca Subject: [PATCH v3 06/13] iio: st_sensors: Add a local lock for protecting odr Date: Mon, 7 Feb 2022 15:38:33 +0100 Message-Id: <20220207143840.707510-7-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220207143840.707510-1-miquel.raynal@bootlin.com> References: <20220207143840.707510-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Right now the (framework) mlock lock is (ab)used for multiple purposes: 1- protecting concurrent accesses over the odr local cache 2- avoid changing samplig frequency whilst buffer is running Let's start by handling situation #1 with a local lock. Suggested-by: Jonathan Cameron Cc: Denis Ciocca Signed-off-by: Miquel Raynal --- .../iio/common/st_sensors/st_sensors_core.c | 24 ++++++++++++++----- include/linux/iio/common/st_sensors.h | 3 +++ 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c index 6c027150a5a4..665584e8bea4 100644 --- a/drivers/iio/common/st_sensors/st_sensors_core.c +++ b/drivers/iio/common/st_sensors/st_sensors_core.c @@ -71,16 +71,18 @@ static int st_sensors_match_odr(struct st_sensor_settings *sensor_settings, int st_sensors_set_odr(struct iio_dev *indio_dev, unsigned int odr) { - int err; + int err = 0; struct st_sensor_odr_avl odr_out = {0, 0}; struct st_sensor_data *sdata = iio_priv(indio_dev); + mutex_lock(&sdata->odr_lock); + if (!sdata->sensor_settings->odr.mask) - return 0; + goto unlock_mutex; err = st_sensors_match_odr(sdata->sensor_settings, odr, &odr_out); if (err < 0) - goto st_sensors_match_odr_error; + goto unlock_mutex; if ((sdata->sensor_settings->odr.addr == sdata->sensor_settings->pw.addr) && @@ -103,7 +105,9 @@ int st_sensors_set_odr(struct iio_dev *indio_dev, unsigned int odr) if (err >= 0) sdata->odr = odr_out.hz; -st_sensors_match_odr_error: +unlock_mutex: + mutex_unlock(&sdata->odr_lock); + return err; } EXPORT_SYMBOL(st_sensors_set_odr); @@ -361,6 +365,8 @@ int st_sensors_init_sensor(struct iio_dev *indio_dev, struct st_sensors_platform_data *of_pdata; int err = 0; + mutex_init(&sdata->odr_lock); + /* If OF/DT pdata exists, it will take precedence of anything else */ of_pdata = st_sensors_dev_probe(indio_dev->dev.parent, pdata); if (IS_ERR(of_pdata)) @@ -554,18 +560,24 @@ int st_sensors_read_info_raw(struct iio_dev *indio_dev, err = -EBUSY; goto out; } else { + mutex_lock(&sdata->odr_lock); err = st_sensors_set_enable(indio_dev, true); - if (err < 0) + if (err < 0) { + mutex_unlock(&sdata->odr_lock); goto out; + } msleep((sdata->sensor_settings->bootime * 1000) / sdata->odr); err = st_sensors_read_axis_data(indio_dev, ch, val); - if (err < 0) + if (err < 0) { + mutex_unlock(&sdata->odr_lock); goto out; + } *val = *val >> ch->scan_type.shift; err = st_sensors_set_enable(indio_dev, false); + mutex_unlock(&sdata->odr_lock); } out: mutex_unlock(&indio_dev->mlock); diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h index 22f67845cdd3..db4a1b260348 100644 --- a/include/linux/iio/common/st_sensors.h +++ b/include/linux/iio/common/st_sensors.h @@ -237,6 +237,7 @@ struct st_sensor_settings { * @hw_irq_trigger: if we're using the hardware interrupt on the sensor. * @hw_timestamp: Latest timestamp from the interrupt handler, when in use. * @buffer_data: Data used by buffer part. + * @odr_lock: Local lock for preventing concurrent ODR accesses/changes */ struct st_sensor_data { struct iio_trigger *trig; @@ -261,6 +262,8 @@ struct st_sensor_data { s64 hw_timestamp; char buffer_data[ST_SENSORS_MAX_BUFFER_SIZE] ____cacheline_aligned; + + struct mutex odr_lock; }; #ifdef CONFIG_IIO_BUFFER