From c49cfc227e7f49e6011d6b955145814ce13424bc Mon Sep 17 00:00:00 2001
From: Alexandru Ardelean <alexandru.ardelean@analog.com>
Date: Fri, 1 Nov 2019 11:35:05 +0200
Subject: [PATCH] iio: imu: adis: assign value only if return code zero in read funcs
Git-commit: c49cfc227e7f49e6011d6b955145814ce13424bc
Patch-mainline: v5.5-rc1
References: git-fixes

The inline read functions in the ADIS library don't check the return value
of the `adis_read_reg()` function and assign the value of `tmp` regardless.

Fix this by checking if return value is zero and only then assigning the
value of `tmp`.

No known case of the callers of this function incorrectly using the
value, but best to stop any potential risk here.
Not suitable for stable due to no known actual bugs caused by this
issue.

Fixes: 57a1228a06b7a ("iio:imu:adis: Add support for 32bit registers")
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 include/linux/iio/imu/adis.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index 4c53815bb729..92aae14593bf 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -129,7 +129,8 @@ static inline int adis_read_reg_16(struct adis *adis, unsigned int reg,
 	int ret;
 
 	ret = adis_read_reg(adis, reg, &tmp, 2);
-	*val = tmp;
+	if (ret == 0)
+		*val = tmp;
 
 	return ret;
 }
@@ -147,7 +148,8 @@ static inline int adis_read_reg_32(struct adis *adis, unsigned int reg,
 	int ret;
 
 	ret = adis_read_reg(adis, reg, &tmp, 4);
-	*val = tmp;
+	if (ret == 0)
+		*val = tmp;
 
 	return ret;
 }
-- 
2.16.4