On Thu, 19 Sep 2019 16:23:03 +0300
Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote:
> The lock is used to protect the buffer during reads. Though the spi
> routines have their own locks, it may be the case that the buffer needs to
> be protected before it's stored and passed to the IIO read hooks.
>
> indio_dev's mlock was used before.
> This change replaces it with the driver's own lock.
>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to poke holes in it.
Thanks,
Jonathan
> ---
> drivers/iio/gyro/adis16080.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/gyro/adis16080.c b/drivers/iio/gyro/adis16080.c
> index 236220d6de02..1b84b8e112fe 100644
> --- a/drivers/iio/gyro/adis16080.c
> +++ b/drivers/iio/gyro/adis16080.c
> @@ -38,10 +38,12 @@ struct adis16080_chip_info {
> * @us: actual spi_device to write data
> * @info: chip specific parameters
> * @buf: transmit or receive buffer
> + * @lock lock to protect buffer during reads
> **/
> struct adis16080_state {
> struct spi_device *us;
> const struct adis16080_chip_info *info;
> + struct mutex lock;
>
> __be16 buf ____cacheline_aligned;
> };
> @@ -82,9 +84,9 @@ static int adis16080_read_raw(struct iio_dev *indio_dev,
>
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> ret = adis16080_read_sample(indio_dev, chan->address, val);
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret ? ret : IIO_VAL_INT;
> case IIO_CHAN_INFO_SCALE:
> switch (chan->type) {
> @@ -196,6 +198,8 @@ static int adis16080_probe(struct spi_device *spi)
> /* this is only used for removal purposes */
> spi_set_drvdata(spi, indio_dev);
>
> + mutex_init(&st->lock);
> +
> /* Allocate the comms buffers */
> st->us = spi;
> st->info = &adis16080_chip_info[id->driver_data];
