There is no reason to have a seperate mutex when indio_dev->mlock can
be used with the iio_device_*_direct_mode helpers. Also avoid a race
condition that is possible with multiple IIO_RESISTANCE reads.
Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
---
drivers/iio/chemical/vz89x.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c
index cd3870ead3fd..5e5d4a9abe63 100644
--- a/drivers/iio/chemical/vz89x.c
+++ b/drivers/iio/chemical/vz89x.c
@@ -16,7 +16,6 @@
*/
#include <linux/module.h>
-#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/of.h>
@@ -52,7 +51,6 @@ struct vz89x_chip_data;
struct vz89x_data {
struct i2c_client *client;
const struct vz89x_chip_data *chip;
- struct mutex lock;
int (*xfer)(struct vz89x_data *data, u8 cmd);
bool is_valid;
@@ -277,26 +275,32 @@ static int vz89x_read_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_RAW:
- mutex_lock(&data->lock);
- ret = vz89x_get_measurement(data);
- mutex_unlock(&data->lock);
-
+ ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
+ ret = vz89x_get_measurement(data);
+ if (ret)
+ goto error_out;
+
switch (chan->type) {
case IIO_CONCENTRATION:
*val = data->buffer[chan->address];
- return IIO_VAL_INT;
+ ret = IIO_VAL_INT;
+ break;
case IIO_RESISTANCE:
ret = vz89x_get_resistance_reading(data, chan, val);
if (!ret)
- return IIO_VAL_INT;
+ ret = IIO_VAL_INT;
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
}
- break;
+
+error_out:
+ iio_device_release_direct_mode(indio_dev);
+
+ return ret;
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_RESISTANCE:
@@ -390,7 +394,6 @@ static int vz89x_probe(struct i2c_client *client,
data->client = client;
data->chip = &vz89x_chips[chip_id];
data->last_update = jiffies - HZ;
- mutex_init(&data->lock);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &vz89x_info,
--
2.7.4
--
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