iio: inkern: fix iio_convert_raw_to_processed_unlocked

commit f91d1b63a4e096d3023aaaafec9d9d3aff25997f upstream.

When reading IIO_CHAN_INFO_OFFSET, the return value of iio_channel_read() for
success will be IIO_VAL*, checking for 0 is not correct.

Without this fix the offset applied by iio drivers will be ignored when
converting a raw value to one in appropriate base units (e.g mV) in
a IIO client drivers that use iio_convert_raw_to_processed including
iio-hwmon.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 98ddc323add011fe84e45abc4f8902ce9e7f09af..0cf5f8e06cfcc6b6bc8c059871e153a391cbd122 100644 (file)
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -451,7 +451,7 @@ static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
        int ret;
 
        ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET);
-       if (ret == 0)
+       if (ret >= 0)
                raw64 += offset;
 
        scale_type = iio_channel_read(chan, &scale_val, &scale_val2,