From: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> [ 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: Jonathan Cameron <jic23@xxxxxxxxxx> Cc: Denis Ciocca <denis.ciocca@xxxxxx> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220207143840.707510-7-miquel.raynal@xxxxxxxxxxx Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- .../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 0bbb090b108c..aff981551617 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); @@ -365,6 +369,8 @@ 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)) @@ -558,18 +564,24 @@ 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 8bdbaf3f3796..69f4a1f6b536 100644 --- a/include/linux/iio/common/st_sensors.h +++ b/include/linux/iio/common/st_sensors.h @@ -238,6 +238,7 @@ 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; @@ -263,6 +264,8 @@ 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 -- 2.35.1
