From 8d6a232f918eac3b5dd05481f9902c1d8f4d5204 Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Wed, 4 Feb 2026 15:00:33 +0100 Subject: iio: dac: ds4424: reject -128 RAW value commit 5187e03b817c26c1c3bcb2645a612ea935c4be89 upstream. The DS442x DAC uses sign-magnitude encoding, so -128 cannot be represented in hardware (7-bit magnitude). Previously, passing -128 resulted in a truncated value that programmed 0mA (magnitude 0) instead of the expected maximum negative current, effectively failing silently. Reject -128 to avoid producing the wrong current. Fixes: d632a2bd8ffc ("iio: dac: ds4422/ds4424 dac driver") Cc: stable@vger.kernel.org Signed-off-by: Oleksij Rempel Reviewed-by: Andy Shevchenko Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/dac/ds4424.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c index a8198ba4f98a..059acca45f64 100644 --- a/drivers/iio/dac/ds4424.c +++ b/drivers/iio/dac/ds4424.c @@ -141,7 +141,7 @@ static int ds4424_write_raw(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_RAW: - if (val < S8_MIN || val > S8_MAX) + if (val <= S8_MIN || val > S8_MAX) return -EINVAL; if (val > 0) { -- cgit v1.2.3