Re: [PATCH] iio: dac: ad5449: Replace indio_dev->mlock with own device lock

[Jonathan Cameron]

On Thu, 14 May 2020 12:01:49 +0300
Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx> 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@xxxxxxxxxx>
Applied.

Thanks,

J
> ---
>  drivers/iio/dac/ad5449.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/dac/ad5449.c b/drivers/iio/dac/ad5449.c
> index fed3ebaccac4..d739b10e5236 100644
> --- a/drivers/iio/dac/ad5449.c
> +++ b/drivers/iio/dac/ad5449.c
> @@ -56,11 +56,13 @@ struct ad5449_chip_info {
>   * @has_sdo:		whether the SDO line is connected
>   * @dac_cache:		Cache for the DAC values
>   * @data:		spi transfer buffers
> + * @lock		lock to protect the data buffer during SPI ops
>   */
>  struct ad5449 {
>  	struct spi_device		*spi;
>  	const struct ad5449_chip_info	*chip_info;
>  	struct regulator_bulk_data	vref_reg[AD5449_MAX_VREFS];
> +	struct mutex			lock;
>  
>  	bool has_sdo;
>  	uint16_t dac_cache[AD5449_MAX_CHANNELS];
> @@ -87,10 +89,10 @@ static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr,
>  	struct ad5449 *st = iio_priv(indio_dev);
>  	int ret;
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(&st->lock);
>  	st->data[0] = cpu_to_be16((addr << 12) | val);
>  	ret = spi_write(st->spi, st->data, 2);
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(&st->lock);
>  
>  	return ret;
>  }
> @@ -112,7 +114,7 @@ static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr,
>  		},
>  	};
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(&st->lock);
>  	st->data[0] = cpu_to_be16(addr << 12);
>  	st->data[1] = cpu_to_be16(AD5449_CMD_NOOP);
>  
> @@ -123,7 +125,7 @@ static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr,
>  	*val = be16_to_cpu(st->data[1]);
>  
>  out_unlock:
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(&st->lock);
>  	return ret;
>  }
>  
> @@ -302,6 +304,8 @@ static int ad5449_spi_probe(struct spi_device *spi)
>  	indio_dev->channels = st->chip_info->channels;
>  	indio_dev->num_channels = st->chip_info->num_channels;
>  
> +	mutex_init(&st->lock);
> +
>  	if (st->chip_info->has_ctrl) {
>  		unsigned int ctrl = 0x00;
>  		if (pdata) {