[PATCH] iio: hi8435: fix race between event enable and event generation

[Nikita Yushchenko]

Add locking to avoid interference between reading/processing current
sence in event enable and event generation paths.

Signed-off-by: Nikita Yushchenko <nikita.yo...@cogentembedded.com>
---
 drivers/iio/adc/hi8435.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/iio/adc/hi8435.c b/drivers/iio/adc/hi8435.c
index ab59969b7c49..28fc699f00f6 100644
--- a/drivers/iio/adc/hi8435.c
+++ b/drivers/iio/adc/hi8435.c
@@ -144,6 +144,8 @@ static int hi8435_write_event_config(struct iio_dev *idev,
        int ret;
        u32 tmp;
 
+       mutex_lock(&priv->lock);
+
        if (state) {
                ret = hi8435_readl(priv, HI8435_SO31_0_REG, &tmp);
                if (ret < 0)
@@ -157,6 +159,8 @@ static int hi8435_write_event_config(struct iio_dev *idev,
        } else
                priv->event_scan_mask &= ~BIT(chan->channel);
 
+       mutex_unlock(&priv->lock);
+
        return 0;
 }
 
@@ -449,12 +453,16 @@ static irqreturn_t hi8435_trigger_handler(int irq, void 
*private)
        u32 val;
        int ret;
 
+       mutex_lock(&priv->lock);
+
        ret = hi8435_readl(priv, HI8435_SO31_0_REG, &val);
        if (ret < 0)
                goto err_read;
 
        hi8435_iio_push_event(idev, val);
 
+       mutex_unlock(&priv->lock);
+
 err_read:
        iio_trigger_notify_done(idev->trig);
 
-- 
2.11.0