[PATCH 3.19.y-ckt 026/146] iio:st_sensors: Fix oops when probing SPI devices

[Kamal Mostafa]

3.19.8-ckt2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alban Bedel <alban.bedel at avionic-design.de>

commit 8e71c04f863a1754f21b27fb8ecb773d680a0a80 upstream.

In SPI mode the transfer buffer is locked with a mutex. However this
mutex is only initilized after the probe, but some transfer needs to
be done in the probe.

To fix this bug we move the mutex initialization at the beginning of
the device probe.

Signed-off-by: Alban Bedel <alban.bedel at avionic-design.de>
Acked-by: Denis Ciocca <denis.ciocca at st.com>
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/iio/accel/st_accel_core.c               | 1 +
 drivers/iio/common/st_sensors/st_sensors_core.c | 2 --
 drivers/iio/gyro/st_gyro_core.c                 | 1 +
 drivers/iio/magnetometer/st_magn_core.c         | 1 +
 drivers/iio/pressure/st_pressure_core.c         | 1 +
 5 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
index 53f3262..6805db0 100644
--- a/drivers/iio/accel/st_accel_core.c
+++ b/drivers/iio/accel/st_accel_core.c
@@ -465,6 +465,7 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
 
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &accel_info;
+	mutex_init(&adata->tb.buf_lock);
 
 	st_sensors_power_enable(indio_dev);
 
diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
index edd13d2..8dd0477 100644
--- a/drivers/iio/common/st_sensors/st_sensors_core.c
+++ b/drivers/iio/common/st_sensors/st_sensors_core.c
@@ -304,8 +304,6 @@ int st_sensors_init_sensor(struct iio_dev *indio_dev,
 	struct st_sensors_platform_data *of_pdata;
 	int err = 0;
 
-	mutex_init(&sdata->tb.buf_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)
diff --git a/drivers/iio/gyro/st_gyro_core.c b/drivers/iio/gyro/st_gyro_core.c
index f07a233..566f7d2 100644
--- a/drivers/iio/gyro/st_gyro_core.c
+++ b/drivers/iio/gyro/st_gyro_core.c
@@ -317,6 +317,7 @@ int st_gyro_common_probe(struct iio_dev *indio_dev)
 
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &gyro_info;
+	mutex_init(&gdata->tb.buf_lock);
 
 	st_sensors_power_enable(indio_dev);
 
diff --git a/drivers/iio/magnetometer/st_magn_core.c b/drivers/iio/magnetometer/st_magn_core.c
index 8ade473..2e56f81 100644
--- a/drivers/iio/magnetometer/st_magn_core.c
+++ b/drivers/iio/magnetometer/st_magn_core.c
@@ -369,6 +369,7 @@ int st_magn_common_probe(struct iio_dev *indio_dev)
 
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &magn_info;
+	mutex_init(&mdata->tb.buf_lock);
 
 	st_sensors_power_enable(indio_dev);
 
diff --git a/drivers/iio/pressure/st_pressure_core.c b/drivers/iio/pressure/st_pressure_core.c
index 97baf40d..e881fa6 100644
--- a/drivers/iio/pressure/st_pressure_core.c
+++ b/drivers/iio/pressure/st_pressure_core.c
@@ -417,6 +417,7 @@ int st_press_common_probe(struct iio_dev *indio_dev)
 
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &press_info;
+	mutex_init(&press_data->tb.buf_lock);
 
 	st_sensors_power_enable(indio_dev);
 
-- 
1.9.1