[PATCH 3.14 33/96] iio: imu: adis16400: Fix sign extension
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2015-03-16 15:01:34
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3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rasmus Villemoes <linux@rasmusvillemoes.dk> commit 19e353f2b344ad86cea6ebbc0002e5f903480a90 upstream. The intention is obviously to sign-extend a 12 bit quantity. But because of C's promotion rules, the assignment is equivalent to "val16 &= 0xfff;". Use the proper API for this. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/iio/imu/adis16400_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/iio/imu/adis16400_core.c
+++ b/drivers/iio/imu/adis16400_core.c@@ -26,6 +26,7 @@ #include <linux/list.h> #include <linux/module.h> #include <linux/debugfs.h> +#include <linux/bitops.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h>
@@ -447,7 +448,7 @@ static int adis16400_read_raw(struct iio mutex_unlock(&indio_dev->mlock); if (ret) return ret; - val16 = ((val16 & 0xFFF) << 4) >> 4; + val16 = sign_extend32(val16, 11); *val = val16; return IIO_VAL_INT; case IIO_CHAN_INFO_OFFSET: