[1/2] staging: iio: adc: ad7192: Replace mlock with driver private lock
diff mbox

Message ID 1506437917-7219-2-git-send-email-aastha.gupta4104@gmail.com
State New
Headers show

Commit Message

Aastha Gupta Sept. 26, 2017, 2:58 p.m. UTC
In this driver, mlock was being used to protect hardware state
changes.  Replace it with a lock in the devices global data.

Signed-off-by: Aastha Gupta <aastha.gupta4104@gmail.com>
---
 drivers/staging/iio/adc/ad7192.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Comments

Julia Lawall Sept. 26, 2017, 3:16 p.m. UTC | #1
On Tue, 26 Sep 2017, Aastha Gupta wrote:

> In this driver, mlock was being used to protect hardware state
> changes.  Replace it with a lock in the devices global data.

At least from the point of view of someone who doesn't know this code, I
think that the commit message could be clearer.  For example, what is
mlock?  Is a special locking function?  A global variable?  It seems that
actually a field in some structre.  Why is the lock of that structure less
appropriate than the lock of the structure that you have chosen?

julia


>
> Signed-off-by: Aastha Gupta <aastha.gupta4104@gmail.com>
> ---
>  drivers/staging/iio/adc/ad7192.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
> index d11c6de..096d29d 100644
> --- a/drivers/staging/iio/adc/ad7192.c
> +++ b/drivers/staging/iio/adc/ad7192.c
> @@ -162,6 +162,7 @@ struct ad7192_state {
>  	u32				scale_avail[8][2];
>  	u8				gpocon;
>  	u8				devid;
> +	struct mutex			lock;
>
>  	struct ad_sigma_delta		sd;
>  };
> @@ -463,10 +464,10 @@ static int ad7192_read_raw(struct iio_dev *indio_dev,
>  	case IIO_CHAN_INFO_SCALE:
>  		switch (chan->type) {
>  		case IIO_VOLTAGE:
> -			mutex_lock(&indio_dev->mlock);
> +			mutex_lock(&st->lock);
>  			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
>  			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
> -			mutex_unlock(&indio_dev->mlock);
> +			mutex_unlock(&st->lock);
>  			return IIO_VAL_INT_PLUS_NANO;
>  		case IIO_TEMP:
>  			*val = 0;
> @@ -634,6 +635,8 @@ static int ad7192_probe(struct spi_device *spi)
>
>  	st = iio_priv(indio_dev);
>
> +	mutex_init(&st->lock);
> +
>  	st->avdd = devm_regulator_get(&spi->dev, "avdd");
>  	if (IS_ERR(st->avdd))
>  		return PTR_ERR(st->avdd);
> --
> 2.7.4
>
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Patch
diff mbox

diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index d11c6de..096d29d 100644
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -162,6 +162,7 @@  struct ad7192_state {
 	u32				scale_avail[8][2];
 	u8				gpocon;
 	u8				devid;
+	struct mutex			lock;
 
 	struct ad_sigma_delta		sd;
 };
@@ -463,10 +464,10 @@  static int ad7192_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_VOLTAGE:
-			mutex_lock(&indio_dev->mlock);
+			mutex_lock(&st->lock);
 			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
 			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
-			mutex_unlock(&indio_dev->mlock);
+			mutex_unlock(&st->lock);
 			return IIO_VAL_INT_PLUS_NANO;
 		case IIO_TEMP:
 			*val = 0;
@@ -634,6 +635,8 @@  static int ad7192_probe(struct spi_device *spi)
 
 	st = iio_priv(indio_dev);
 
+	mutex_init(&st->lock);
+
 	st->avdd = devm_regulator_get(&spi->dev, "avdd");
 	if (IS_ERR(st->avdd))
 		return PTR_ERR(st->avdd);