From a6b5eb09bddbd0c331f41fefa2fd2f71a2cf9455 Mon Sep 17 00:00:00 2001
From: Vasily Khoruzhick <anarsoul@gmail.com>
Date: Tue, 24 Apr 2018 22:21:10 -0700
Subject: [PATCH 036/146] sun4i-gpadc-iio: ignore zero samples to avoid force
 poweroff when reading first sample

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
---
 drivers/iio/adc/sun4i-gpadc-iio.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
index fdfa01bad325..68256e73a4d2 100644
--- a/drivers/iio/adc/sun4i-gpadc-iio.c
+++ b/drivers/iio/adc/sun4i-gpadc-iio.c
@@ -751,6 +751,12 @@ static int sun4i_gpadc_get_temp(void *data, int *temp)
 	if (sun4i_gpadc_temp_read(info->indio_dev, &val, info->sensor_id))
 		return -ETIMEDOUT;
 
+	/* Ignore first sample which is always zero. 0 is either too
+	 * cold or too hot, so we can safely ignore it
+	 */
+	if (val == 0)
+		return -ETIMEDOUT;
+
 	sun4i_gpadc_temp_scale(info->indio_dev, &scale);
 	sun4i_gpadc_temp_offset(info->indio_dev, &offset);
 
-- 
2.17.1

