From 171c0091837c81ed5c949fec6966bb5afff2d1cf Mon Sep 17 00:00:00 2001 From: Gregor Boirie Date: Fri, 2 Sep 2016 20:27:46 +0200 Subject: [PATCH] iio:core: fix IIO_VAL_FRACTIONAL sign handling 7985e7c100 ("iio: Introduce a new fractional value type") introduced a new IIO_VAL_FRACTIONAL value type meant to represent rational type numbers expressed by a numerator and denominator combination. Formating of IIO_VAL_FRACTIONAL values relies upon do_div() usage. This fails handling negative values properly since parameters are reevaluated as unsigned values. Fix this by using div_s64_rem() instead. Computed integer part will carry properly signed value. Formatted fractional part will always be positive. Fixes: 7985e7c100 ("iio: Introduce a new fractional value type") Signed-off-by: Gregor Boirie Reviewed-by: Lars-Peter Clausen Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-core.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index f914d5d..d2b8899 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -613,9 +613,8 @@ ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals) return sprintf(buf, "%d.%09u\n", vals[0], vals[1]); case IIO_VAL_FRACTIONAL: tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]); - vals[1] = do_div(tmp, 1000000000LL); - vals[0] = tmp; - return sprintf(buf, "%d.%09u\n", vals[0], vals[1]); + vals[0] = (int)div_s64_rem(tmp, 1000000000, &vals[1]); + return sprintf(buf, "%d.%09u\n", vals[0], abs(vals[1])); case IIO_VAL_FRACTIONAL_LOG2: tmp = (s64)vals[0] * 1000000000LL >> vals[1]; vals[1] = do_div(tmp, 1000000000LL); -- 2.7.4