Re: [PATCHv2 2/3] iio: dht11: Add locking

[sanjeev sharma <sanjeevsharmaengg@gmail.com>]

On Mon, Jan 5, 2015 at 7:21 PM, Harald Geyer <harald@ccbib.org> wrote:
> Make sure that the read function is not interrupted...
>
> Signed-off-by: Richard Weinberger <richard@nod.at>
> Acked-by: Harald Geyer <harald@ccbib.org>
   Reviewed-by: Sanjeev Sharma <sanjeev_sharma@mentor.com>
> ---
> Resending for Richard Weinberger.
> No changes since v1 except reordering.
>
>  drivers/iio/humidity/dht11.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/iio/humidity/dht11.c b/drivers/iio/humidity/dht11.c
> index f546eca..7717f5c 100644
> --- a/drivers/iio/humidity/dht11.c
> +++ b/drivers/iio/humidity/dht11.c
> @@ -29,6 +29,7 @@
>  #include <linux/wait.h>
>  #include <linux/bitops.h>
>  #include <linux/completion.h>
> +#include <linux/mutex.h>
>  #include <linux/delay.h>
>  #include <linux/gpio.h>
>  #include <linux/of_gpio.h>
> @@ -57,6 +58,7 @@ struct dht11 {
>         int                             irq;
>
>         struct completion               completion;
> +       struct mutex                    lock;
>
>         s64                             timestamp;
>         int                             temperature;
> @@ -145,6 +147,7 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
>         struct dht11 *dht11 = iio_priv(iio_dev);
>         int ret;
>
> +       mutex_lock(&dht11->lock);
>         if (dht11->timestamp + DHT11_DATA_VALID_TIME < iio_get_time_ns()) {
>                 reinit_completion(&dht11->completion);
>
> @@ -185,6 +188,7 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
>                 ret = -EINVAL;
>  err:
>         dht11->num_edges = -1;
> +       mutex_unlock(&dht11->lock);
>         return ret;
>  }
>
> @@ -268,6 +272,7 @@ static int dht11_probe(struct platform_device *pdev)
>         platform_set_drvdata(pdev, iio);
>
>         init_completion(&dht11->completion);
> +       mutex_init(&dht11->lock);
>         iio->name = pdev->name;
>         iio->dev.parent = &pdev->dev;
>         iio->info = &dht11_iio_info;
> --
> 1.7.2.5
>
> --
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