6.6-stable review patch. If anyone has any objections, please let me know.
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From: Vasileios Amoiridis vassilisamir@gmail.com
[ Upstream commit 77641e5a477d428335cd094b88ac54e09ccb70f4 ]
Add mutexes in the {read/write}_raw() functions of the device to guard the read/write of data from/to the device. This is necessary because for any operation other than temperature, multiple reads need to take place from the device. Even though regmap has a locking by itself, it won't protect us from multiple applications trying to read at the same time temperature and pressure since the pressure reading includes an internal temperature reading and there is nothing to ensure that this temperature+pressure reading will happen sequentially without any other operation interfering in the meantime.
Fixes: 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor") Signed-off-by: Vasileios Amoiridis vassilisamir@gmail.com Link: https://patch.msgid.link/20240609233826.330516-2-vassilisamir@gmail.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iio/chemical/bme680_core.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c index 500f56834b01f..a6bf689833dad 100644 --- a/drivers/iio/chemical/bme680_core.c +++ b/drivers/iio/chemical/bme680_core.c @@ -10,6 +10,7 @@ */ #include <linux/acpi.h> #include <linux/bitfield.h> +#include <linux/cleanup.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/module.h> @@ -52,6 +53,7 @@ struct bme680_calib { struct bme680_data { struct regmap *regmap; struct bme680_calib bme680; + struct mutex lock; /* Protect multiple serial R/W ops to device. */ u8 oversampling_temp; u8 oversampling_press; u8 oversampling_humid; @@ -827,6 +829,8 @@ static int bme680_read_raw(struct iio_dev *indio_dev, { struct bme680_data *data = iio_priv(indio_dev);
+ guard(mutex)(&data->lock); + switch (mask) { case IIO_CHAN_INFO_PROCESSED: switch (chan->type) { @@ -871,6 +875,8 @@ static int bme680_write_raw(struct iio_dev *indio_dev, { struct bme680_data *data = iio_priv(indio_dev);
+ guard(mutex)(&data->lock); + if (val2 != 0) return -EINVAL;
@@ -967,6 +973,7 @@ int bme680_core_probe(struct device *dev, struct regmap *regmap, name = bme680_match_acpi_device(dev);
data = iio_priv(indio_dev); + mutex_init(&data->lock); dev_set_drvdata(dev, indio_dev); data->regmap = regmap; indio_dev->name = name;