[PATCH AUTOSEL 4.20 003/304] staging: iio: adc: ad7280a: handle error from __ad7280_read32()

[Sasha Levin]

From: Slawomir Stepien <s...@poczta.fm>

[ Upstream commit 0559ef7fde67bc6c83c6eb6329dbd6649528263e ]

Inside __ad7280_read32(), the spi_sync_transfer() can fail with negative
error code. This change will ensure that this error is being passed up
in the call stack, so it can be handled.

Signed-off-by: Slawomir Stepien <s...@poczta.fm>
Signed-off-by: Jonathan Cameron <jonathan.came...@huawei.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/staging/iio/adc/ad7280a.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/iio/adc/ad7280a.c 
b/drivers/staging/iio/adc/ad7280a.c
index 58420dcb406d..cbeb52485a31 100644
--- a/drivers/staging/iio/adc/ad7280a.c
+++ b/drivers/staging/iio/adc/ad7280a.c
@@ -256,7 +256,9 @@ static int ad7280_read(struct ad7280_state *st, unsigned 
int devaddr,
        if (ret)
                return ret;
 
-       __ad7280_read32(st, &tmp);
+       ret = __ad7280_read32(st, &tmp);
+       if (ret)
+               return ret;
 
        if (ad7280_check_crc(st, tmp))
                return -EIO;
@@ -294,7 +296,9 @@ static int ad7280_read_channel(struct ad7280_state *st, 
unsigned int devaddr,
 
        ad7280_delay(st);
 
-       __ad7280_read32(st, &tmp);
+       ret = __ad7280_read32(st, &tmp);
+       if (ret)
+               return ret;
 
        if (ad7280_check_crc(st, tmp))
                return -EIO;
@@ -327,7 +331,9 @@ static int ad7280_read_all_channels(struct ad7280_state 
*st, unsigned int cnt,
        ad7280_delay(st);
 
        for (i = 0; i < cnt; i++) {
-               __ad7280_read32(st, &tmp);
+               ret = __ad7280_read32(st, &tmp);
+               if (ret)
+                       return ret;
 
                if (ad7280_check_crc(st, tmp))
                        return -EIO;
@@ -370,7 +376,10 @@ static int ad7280_chain_setup(struct ad7280_state *st)
                return ret;
 
        for (n = 0; n <= AD7280A_MAX_CHAIN; n++) {
-               __ad7280_read32(st, &val);
+               ret = __ad7280_read32(st, &val);
+               if (ret)
+                       return ret;
+
                if (val == 0)
                        return n - 1;
 
-- 
2.19.1