[PATCH 4.7 079/184] iio: accel: kxsd9: Fix scaling bug

From: Greg Kroah-Hartman
Date: Thu Sep 22 2016 - 14:26:10 EST


4.7-stable review patch. If anyone has any objections, please let me know.

------------------

From: Linus Walleij <linus.walleij@xxxxxxxxxx>

commit 307fe9dd11ae44d4f8881ee449a7cbac36e1f5de upstream.

All the scaling of the KXSD9 involves multiplication with a
fraction number < 1.

However the scaling value returned from IIO_INFO_SCALE was
unpredictable as only the micros of the value was assigned, and
not the integer part, resulting in scaling like this:

$cat in_accel_scale
-1057462640.011978

Fix this by assigning zero to the integer part.

Tested-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/iio/accel/kxsd9.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/iio/accel/kxsd9.c
+++ b/drivers/iio/accel/kxsd9.c
@@ -166,6 +166,7 @@ static int kxsd9_read_raw(struct iio_dev
ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
if (ret < 0)
goto error_ret;
+ *val = 0;
*val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
ret = IIO_VAL_INT_PLUS_MICRO;
break;