Commit 51593106 authored by Liam Beguin's avatar Liam Beguin Committed by Jonathan Cameron
Browse files

iio: afe: rescale: use s64 for temporary scale calculations 



All four scaling coefficients can take signed values.
Make tmp a signed 64-bit integer and switch to div_s64() to preserve
signs during 64-bit divisions.

Fixes: 8b74816b ("iio: afe: rescale: new driver")
Signed-off-by: default avatarLiam Beguin <liambeguin@gmail.com>
Reviewed-by: default avatarPeter Rosin <peda@axentia.se>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220108205319.2046348-5-liambeguin@gmail.com


Cc: <Stable@vger.kernel.org>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent ca851233

drivers/iio/afe/iio-rescale.c

+4 −4
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ static int rescale_read_raw(struct iio_dev *indio_dev, 
			    int *val, int *val2, long mask)

{

	struct rescale *rescale = iio_priv(indio_dev);

	unsigned long long tmp;

	s64 tmp;

	int ret;



	switch (mask) {
@@ -77,10 +77,10 @@ static int rescale_read_raw(struct iio_dev *indio_dev, 
			*val2 = rescale->denominator;

			return IIO_VAL_FRACTIONAL;

		case IIO_VAL_FRACTIONAL_LOG2:

			tmp = *val * 1000000000LL;

			do_div(tmp, rescale->denominator);

			tmp = (s64)*val * 1000000000LL;

			tmp = div_s64(tmp, rescale->denominator);

			tmp *= rescale->numerator;

			do_div(tmp, 1000000000LL);

			tmp = div_s64(tmp, 1000000000LL);

			*val = tmp;

			return ret;

		default: