[2/2] staging: iio: adc: ad7192: add lock to protect hardware state changes
diff mbox

Message ID 1506437917-7219-3-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, private driver lock is being used to protect hardware
state changes.

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

Comments

Julia Lawall Sept. 26, 2017, 3:17 p.m. UTC | #1
On Tue, 26 Sep 2017, Aastha Gupta wrote:

> In this driver, private driver lock is being used to protect hardware
> state changes.

Similarly, in this case, why is this the good lock to use, and why is this
the good place to put it?

julia

>
> Signed-off-by: Aastha Gupta <aastha.gupta4104@gmail.com>
> ---
>  drivers/staging/iio/adc/ad7192.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
> index 096d29d..609a649 100644
> --- a/drivers/staging/iio/adc/ad7192.c
> +++ b/drivers/staging/iio/adc/ad7192.c
> @@ -511,6 +511,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
>  	switch (mask) {
>  	case IIO_CHAN_INFO_SCALE:
>  		ret = -EINVAL;
> +		mutex_lock(&st->lock);
>  		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
>  			if (val2 == st->scale_avail[i][1]) {
>  				ret = 0;
> @@ -524,6 +525,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
>  				ad7192_calibrate_all(st);
>  				break;
>  			}
> +		mutex_unlock(&st->lock);
>  		break;
>  	case IIO_CHAN_INFO_SAMP_FREQ:
>  		if (!val) {
> --
> 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 096d29d..609a649 100644
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -511,6 +511,7 @@  static int ad7192_write_raw(struct iio_dev *indio_dev,
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		ret = -EINVAL;
+		mutex_lock(&st->lock);
 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
 			if (val2 == st->scale_avail[i][1]) {
 				ret = 0;
@@ -524,6 +525,7 @@  static int ad7192_write_raw(struct iio_dev *indio_dev,
 				ad7192_calibrate_all(st);
 				break;
 			}
+		mutex_unlock(&st->lock);
 		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (!val) {