iio: adc: ina219: Avoid underflow for sleeping time

Proper support for the INA219 lowered the minimum sampling period from
2*140us to 2*84us. Subtracting 200us later leads to an underflow and
an almost infinite udelay later.

Using a signed int for the sampling period provides sufficient range
(at most 2*8640*1024us), but catches the underflow when comparing with
buffer_us.

Fixes: 18edac2e22f4 ("iio: adc: Fix integration time/averaging for INA219/220")
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
index 232c0b80d65893e497abe4e13c4b5273e3c9a7a0..c3f86138cb55eba108cb39ef5c10548ad13ff5a4 100644 (file)
--- a/drivers/iio/adc/ina2xx-adc.c
+++ b/drivers/iio/adc/ina2xx-adc.c
@@ -644,7 +644,7 @@ static int ina2xx_capture_thread(void *data)
 {
        struct iio_dev *indio_dev = data;
        struct ina2xx_chip_info *chip = iio_priv(indio_dev);
-       unsigned int sampling_us = SAMPLING_PERIOD(chip);
+       int sampling_us = SAMPLING_PERIOD(chip);
        int buffer_us;
 
        /*