On 20/03/17 14:12, Arushi Singhal wrote:
> The IIO subsystem is redefining iio_dev->mlock to be used by
> the IIO core only for protecting device operating mode changes.
> ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.
>
> 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: Arushi Singhal <arushisinghal19971997@xxxxxxxxx>
mutex_init?
This partly came from the fact Alison missed it in her example
patch (and I didn't notice!), but all mutexes need to be initialized
before use. It's an interesting diversion to follow what that actually
does... There is more to a mutex than you might expect!
Jonathan
> ---
> drivers/staging/iio/adc/ad7606.c | 8 ++++----
> drivers/staging/iio/adc/ad7606.h | 2 ++
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/staging/iio/adc/ad7606.c b/drivers/staging/iio/adc/ad7606.c
> index 9dbfa64b1e53..9f529b34e018 100644
> --- a/drivers/staging/iio/adc/ad7606.c
> +++ b/drivers/staging/iio/adc/ad7606.c
> @@ -208,7 +208,7 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
> switch (mask) {
> case IIO_CHAN_INFO_SCALE:
> ret = -EINVAL;
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> for (i = 0; i < ARRAY_SIZE(scale_avail); i++)
> if (val2 == scale_avail[i][1]) {
> gpiod_set_value(st->gpio_range, i);
> @@ -217,7 +217,7 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
> ret = 0;
> break;
> }
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
>
> return ret;
> case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> @@ -231,11 +231,11 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
> values[1] = (ret >> 1) & 1;
> values[2] = (ret >> 2) & 1;
>
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
> values);
> st->oversampling = val;
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
>
> return 0;
> default:
> diff --git a/drivers/staging/iio/adc/ad7606.h b/drivers/staging/iio/adc/ad7606.h
> index 746f9553d2ba..5d59bdd78727 100644
> --- a/drivers/staging/iio/adc/ad7606.h
> +++ b/drivers/staging/iio/adc/ad7606.h
> @@ -14,6 +14,7 @@
> * @name: identification string for chip
> * @channels: channel specification
> * @num_channels: number of channels
> + * @lock protect sensor state
> */
>
> struct ad7606_chip_info {
> @@ -37,6 +38,7 @@ struct ad7606_state {
> bool done;
> void __iomem *base_address;
>
> + struct mutex lock; /* protect sensor state */
> struct gpio_desc *gpio_convst;
> struct gpio_desc *gpio_reset;
> struct gpio_desc *gpio_range;
>
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
