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iio: st_sensors: Add a local lock for protecting odr

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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 <jic23@kernel.org>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220207143840.707510-7-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Miquel Raynal 2022-02-07 15:38:33 +01:00 committed by Jonathan Cameron
parent 05a32f1aeb
commit 474010127e
2 changed files with 21 additions and 6 deletions
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24
drivers/iio/common/st_sensors/st_sensors_core.c
View File

@ -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_NS(st_sensors_set_odr, IIO_ST_SENSORS);
@ -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);

3
include/linux/iio/common/st_sensors.h
View File

@ -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