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| author | Gregor Boirie <gregor.boirie@parrot.com> | 2016-09-02 20:27:46 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-24 10:09:31 +0200 |
| commit | a3a4fce551ff24b53e04825b9cde6de126888768 (patch) | |
| tree | 3c52ea19c9f7fe349f835fd5dc8858bee70b7042 | |
| parent | f0bb3dd494eb7b04296595f5679720668055aebf (diff) | |
| download | lwn-a3a4fce551ff24b53e04825b9cde6de126888768.tar.gz lwn-a3a4fce551ff24b53e04825b9cde6de126888768.zip | |
iio:core: fix IIO_VAL_FRACTIONAL sign handling
commit 171c0091837c81ed5c949fec6966bb5afff2d1cf upstream.
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 <gregor.boirie@parrot.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/iio/industrialio-core.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index e6319a9346b2..2e6a427588e1 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -532,9 +532,8 @@ 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); |