[3.13.y-ckt stable] Patch "iio: imu: adis16400: Fix sign extension" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    iio: imu: adis16400: Fix sign extension

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt19.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From c7587a4d94f9e34242434753ac4ec275440deaa7 Mon Sep 17 00:00:00 2001
From: Rasmus Villemoes <linux at rasmusvillemoes.dk>
Date: Fri, 23 Jan 2015 00:34:02 +0100
Subject: iio: imu: adis16400: Fix sign extension

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 at rasmusvillemoes.dk>
Acked-by: Lars-Peter Clausen <lars at metafoo.de>
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/iio/imu/adis16400_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/imu/adis16400_core.c b/drivers/iio/imu/adis16400_core.c
index 7c582f7..70753bf 100644
--- 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_dev *indio_dev,
 		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:
--
1.9.1