Re: [PATCH] iio: dac: ad5761: Replace indio_dev->mlock with own device lock

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 14 May 2020 12:10:28 +0300
Sergiu Cuciurean <sergiu.cuciurean@analog.com> wrote:

> As part of the general cleanup of indio_dev->mlock, this change replaces
> it with a local lock on the device's state structure.
> 
> Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Applied to the togreg branch of iio.git.

Thanks,

J
> ---
>  drivers/iio/dac/ad5761.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/dac/ad5761.c b/drivers/iio/dac/ad5761.c
> index 4fb42b743f0f..67179944e5c5 100644
> --- a/drivers/iio/dac/ad5761.c
> +++ b/drivers/iio/dac/ad5761.c
> @@ -57,11 +57,13 @@ enum ad5761_supported_device_ids {
>   * @use_intref:		true when the internal voltage reference is used
>   * @vref:		actual voltage reference in mVolts
>   * @range:		output range mode used
> + * @lock		lock to protect the data buffer during SPI ops
>   * @data:		cache aligned spi buffer
>   */
>  struct ad5761_state {
>  	struct spi_device		*spi;
>  	struct regulator		*vref_reg;
> +	struct mutex			lock;
>  
>  	bool use_intref;
>  	int vref;
> @@ -124,9 +126,9 @@ static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val)
>  	struct ad5761_state *st = iio_priv(indio_dev);
>  	int ret;
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(&st->lock);
>  	ret = _ad5761_spi_write(st, addr, val);
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(&st->lock);
>  
>  	return ret;
>  }
> @@ -163,9 +165,9 @@ static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val)
>  	struct ad5761_state *st = iio_priv(indio_dev);
>  	int ret;
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(&st->lock);
>  	ret = _ad5761_spi_read(st, addr, val);
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(&st->lock);
>  
>  	return ret;
>  }
> @@ -368,6 +370,8 @@ static int ad5761_probe(struct spi_device *spi)
>  	if (pdata)
>  		voltage_range = pdata->voltage_range;
>  
> +	mutex_init(&st->lock);
> +
>  	ret = ad5761_spi_set_range(st, voltage_range);
>  	if (ret)
>  		goto disable_regulator_err;