Re: [PATCH v2 05/16] iio: adc: ltc2947-core: do not use internal iio_dev lock

Jonathan Cameron
2022-10-09T11:58:44Z

On Tue, 4 Oct 2022 15:48:58 +0200
Nuno Sá <nuno.sa@analog.com> wrote:

> The iio_device lock is only meant for internal use. Hence define a
> device local lock to protect against concurrent accesses.
>
> While at it, properly include "mutex.h" for mutex related APIs.
>
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Applied

> ---
> drivers/iio/adc/ltc2497-core.c | 7 +++++--
> drivers/iio/adc/ltc2497.h | 2 ++
> 2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/ltc2497-core.c b/drivers/iio/adc/ltc2497-core.c
> index f52d37af4d1f..996f6cbbed3c 100644
> --- a/drivers/iio/adc/ltc2497-core.c
> +++ b/drivers/iio/adc/ltc2497-core.c
> @@ -10,6 +10,7 @@
> #include <linux/iio/iio.h>
> #include <linux/iio/driver.h>
> #include <linux/module.h>
> +#include <linux/mutex.h>
> #include <linux/regulator/consumer.h>
>
> #include "ltc2497.h"
> @@ -81,9 +82,9 @@ static int ltc2497core_read_raw(struct iio_dev *indio_dev,
>
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&ddata->lock);
> ret = ltc2497core_read(ddata, chan->address, val);
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&ddata->lock);
> if (ret < 0)
> return ret;
>
> @@ -214,6 +215,8 @@ int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
> ddata->addr_prev = LTC2497_CONFIG_DEFAULT;
> ddata->time_prev = ktime_get();
>
> + mutex_init(&ddata->lock);
> +
> ret = iio_device_register(indio_dev);
> if (ret < 0)
> goto err_array_unregister;
> diff --git a/drivers/iio/adc/ltc2497.h b/drivers/iio/adc/ltc2497.h
> index e023de0d88c4..781519b52475 100644
> --- a/drivers/iio/adc/ltc2497.h
> +++ b/drivers/iio/adc/ltc2497.h
> @@ -12,6 +12,8 @@ struct ltc2497_chip_info {
> struct ltc2497core_driverdata {
> struct regulator *ref;
> ktime_t time_prev;
> + /* lock to protect against multiple access to the device */
> + struct mutex lock;
> const struct ltc2497_chip_info *chip_info;
> u8 addr_prev;
> int (*result_and_measure)(struct ltc2497core_driverdata *ddata,