From c459b27945978d3affb01e8c251c991adc045c19 Mon Sep 17 00:00:00 2001 From: Liam Beguin Date: Sat, 8 Jan 2022 15:53:07 -0500 Subject: [PATCH] iio: afe: rescale: use s64 for temporary scale calculations commit 51593106b608ae4247cc8da928813347da16d025 upstream. 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: 8b74816b5a9a ("iio: afe: rescale: new driver") Signed-off-by: Liam Beguin Reviewed-by: Peter Rosin Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220108205319.2046348-5-liambeguin@gmail.com Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/afe/iio-rescale.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c index e9ceee66d1e7..d9c41db8155f 100644 --- a/drivers/iio/afe/iio-rescale.c +++ b/drivers/iio/afe/iio-rescale.c @@ -38,7 +38,7 @@ 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) { @@ -59,10 +59,10 @@ 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: