Re: [PATCH] iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 26 Aug 2020 09:40:28 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> From: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
> 
> 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>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
>  drivers/iio/dac/ti-dac7612.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/dac/ti-dac7612.c b/drivers/iio/dac/ti-dac7612.c
> index 07c9f39d54f1..34c2aec204ef 100644
> --- a/drivers/iio/dac/ti-dac7612.c
> +++ b/drivers/iio/dac/ti-dac7612.c
> @@ -21,6 +21,7 @@ struct dac7612 {
>  	struct spi_device *spi;
>  	struct gpio_desc *loaddacs;
>  	uint16_t cache[2];
> +	struct mutex lock;
Looks fine with the exception of my usual request for a comment explaining
lock scope.

Thanks,

Jonathan

>  
>  	/*
>  	 * DMA (thus cache coherency maintenance) requires the
> @@ -101,9 +102,9 @@ static int dac7612_write_raw(struct iio_dev *iio_dev,
>  	if (val == priv->cache[chan->channel])
>  		return 0;
>  
> -	mutex_lock(&iio_dev->mlock);
> +	mutex_lock(&priv->lock);
>  	ret = dac7612_cmd_single(priv, chan->channel, val);
> -	mutex_unlock(&iio_dev->mlock);
> +	mutex_unlock(&priv->lock);
>  
>  	return ret;
>  }
> @@ -145,6 +146,8 @@ static int dac7612_probe(struct spi_device *spi)
>  	iio_dev->num_channels = ARRAY_SIZE(priv->cache);
>  	iio_dev->name = spi_get_device_id(spi)->name;
>  
> +	mutex_init(&priv->lock);
> +
>  	for (i = 0; i < ARRAY_SIZE(priv->cache); i++) {
>  		ret = dac7612_cmd_single(priv, i, 0);
>  		if (ret)