Re: [PATCH 2/5] iio: amplifiers: ad8366: use own lock to guard state

[Jonathan Cameron <jic23@jic23.retrosnub.co.uk>]

On Thu, 30 May 2019 16:18:09 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> This driver is still using iio_dev's mlock to guard against inconsistent
> state. This has been discouraged for some time.
> 
> This change switches to using it's own mutex, defined on the state struct.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Applied,

Thanks,

Jonathan

> ---
>  drivers/iio/amplifiers/ad8366.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/amplifiers/ad8366.c b/drivers/iio/amplifiers/ad8366.c
> index 82ac15914ff3..24ff5475d9f2 100644
> --- a/drivers/iio/amplifiers/ad8366.c
> +++ b/drivers/iio/amplifiers/ad8366.c
> @@ -21,6 +21,7 @@
>  struct ad8366_state {
>  	struct spi_device	*spi;
>  	struct regulator	*reg;
> +	struct mutex            lock; /* protect sensor state */
>  	unsigned char		ch[2];
>  	/*
>  	 * DMA (thus cache coherency maintenance) requires the
> @@ -58,7 +59,7 @@ static int ad8366_read_raw(struct iio_dev *indio_dev,
>  	int ret;
>  	unsigned code;
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(&st->lock);
>  	switch (m) {
>  	case IIO_CHAN_INFO_HARDWAREGAIN:
>  		code = st->ch[chan->channel];
> @@ -73,7 +74,7 @@ static int ad8366_read_raw(struct iio_dev *indio_dev,
>  	default:
>  		ret = -EINVAL;
>  	}
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(&st->lock);
>  
>  	return ret;
>  };
> @@ -99,7 +100,7 @@ static int ad8366_write_raw(struct iio_dev *indio_dev,
>  
>  	code = (code - 4500) / 253;
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(&st->lock);
>  	switch (mask) {
>  	case IIO_CHAN_INFO_HARDWAREGAIN:
>  		st->ch[chan->channel] = code;
> @@ -108,7 +109,7 @@ static int ad8366_write_raw(struct iio_dev *indio_dev,
>  	default:
>  		ret = -EINVAL;
>  	}
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(&st->lock);
>  
>  	return ret;
>  }
> @@ -151,6 +152,7 @@ static int ad8366_probe(struct spi_device *spi)
>  	}
>  
>  	spi_set_drvdata(spi, indio_dev);
> +	mutex_init(&st->lock);
>  	st->spi = spi;
>  
>  	indio_dev->dev.parent = &spi->dev;