1 files changed, 12 insertions, 4 deletions

diff --git a/kernel/drivers/iio/adc/ti_am335x_adc.c b/kernel/drivers/iio/adc/ti_am335x_adc.c
index c1e05532d..0470fc843 100644
--- a/kernel/drivers/iio/adc/ti_am335x_adc.c
+++ b/kernel/drivers/iio/adc/ti_am335x_adc.c
@@ -32,6 +32,7 @@
 
 struct tiadc_device {
 	struct ti_tscadc_dev *mfd_tscadc;
+	struct mutex fifo1_lock; /* to protect fifo access */
 	int channels;
 	u8 channel_line[8];
 	u8 channel_step[8];
@@ -360,6 +361,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 		int *val, int *val2, long mask)
 {
 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	int ret = IIO_VAL_INT;
 	int i, map_val;
 	unsigned int fifo1count, read, stepid;
 	bool found = false;
@@ -373,13 +375,14 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 	if (!step_en)
 		return -EINVAL;
 
+	mutex_lock(&adc_dev->fifo1_lock);
 	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
 	while (fifo1count--)
 		tiadc_readl(adc_dev, REG_FIFO1);
 
 	am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
 
-	timeout = jiffies + usecs_to_jiffies
+	timeout = jiffies + msecs_to_jiffies
 				(IDLE_TIMEOUT * adc_dev->channels);
 	/* Wait for Fifo threshold interrupt */
 	while (1) {
@@ -389,7 +392,8 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 
 		if (time_after(jiffies, timeout)) {
 			am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
-			return -EAGAIN;
+			ret = -EAGAIN;
+			goto err_unlock;
 		}
 	}
 	map_val = adc_dev->channel_step[chan->scan_index];
@@ -415,8 +419,11 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 	am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
 
 	if (found == false)
-		return -EBUSY;
-	return IIO_VAL_INT;
+		ret =  -EBUSY;
+
+err_unlock:
+	mutex_unlock(&adc_dev->fifo1_lock);
+	return ret;
 }
 
 static const struct iio_info tiadc_info = {
@@ -485,6 +492,7 @@ static int tiadc_probe(struct platform_device *pdev)
 
 	tiadc_step_config(indio_dev);
 	tiadc_writel(adc_dev, REG_FIFO1THR, FIFO1_THRESHOLD);
+	mutex_init(&adc_dev->fifo1_lock);
 
 	err = tiadc_channel_init(indio_dev, adc_dev->channels);
 	if (err < 0)