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Commit ca2498cc authored by Miquel Raynal's avatar Miquel Raynal Committed by Greg Kroah-Hartman
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iio: st_sensors: Add a local lock for protecting odr 



[ Upstream commit 474010127e2505fc463236470908e1ff5ddb3578 ]

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: default avatarJonathan Cameron <jic23@kernel.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220207143840.707510-7-miquel.raynal@bootlin.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent ab75e023

drivers/iio/common/st_sensors/st_sensors_core.c

+18 −6
Original line number Diff line number Diff line
@@ -76,16 +76,18 @@ 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) &&
@@ -108,7 +110,9 @@ 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);
@@ -384,6 +388,8 @@ 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_of_probe(indio_dev->dev.parent, pdata);

	if (of_pdata)
@@ -575,18 +581,24 @@ 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);

include/linux/iio/common/st_sensors.h

+3 −0
Original line number Diff line number Diff line
@@ -228,6 +228,7 @@ 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 device *dev;
@@ -253,6 +254,8 @@ 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