Re: [PATCH v2 11/16] iio: common: scmi_iio: do not use internal iio_dev lock

Jonathan Cameron
2022-10-09T12:09:28Z

On Tue, 4 Oct 2022 15:49:04 +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 to the togreg branch of iio.git, but for now only pushed out as testing
as I'll be rebasing on rc1 once available.

Thanks,

Jonathan

> ---
> drivers/iio/common/scmi_sensors/scmi_iio.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
> index 54ccf19ab2bb..d92f7f651f7b 100644
> --- a/drivers/iio/common/scmi_sensors/scmi_iio.c
> +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
> @@ -15,6 +15,7 @@
> #include <linux/kernel.h>
> #include <linux/kthread.h>
> #include <linux/module.h>
> +#include <linux/mutex.h>
> #include <linux/scmi_protocol.h>
> #include <linux/time.h>
> #include <linux/types.h>
> @@ -27,6 +28,8 @@ struct scmi_iio_priv {
> struct scmi_protocol_handle *ph;
> const struct scmi_sensor_info *sensor_info;
> struct iio_dev *indio_dev;
> + /* lock to protect against multiple access to the device */
> + struct mutex lock;
> /* adding one additional channel for timestamp */
> s64 iio_buf[SCMI_IIO_NUM_OF_AXIS + 1];
> struct notifier_block sensor_update_nb;
> @@ -198,13 +201,14 @@ static int scmi_iio_write_raw(struct iio_dev *iio_dev,
> struct iio_chan_spec const *chan, int val,
> int val2, long mask)
> {
> + struct scmi_iio_priv *sensor = iio_priv(iio_dev);
> int err;
>
> switch (mask) {
> case IIO_CHAN_INFO_SAMP_FREQ:
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&sensor->lock);
> err = scmi_iio_set_odr_val(iio_dev, val, val2);
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&sensor->lock);
> return err;
> default:
> return -EINVAL;
> @@ -586,6 +590,7 @@ scmi_alloc_iiodev(struct scmi_device *sdev,
> sensor->sensor_info = sensor_info;
> sensor->sensor_update_nb.notifier_call = scmi_iio_sensor_update_cb;
> sensor->indio_dev = iiodev;
> + mutex_init(&sensor->lock);
>
> /* adding one additional channel for timestamp */
> iiodev->num_channels = sensor_info->num_axis + 1;