iio: core: Return error for failed read_reg

If an IIO device returns an error code for a read access via debugfs, it
is currently ignored by the IIO core (other than emitting an error
message). Instead, return this error code to user space, so upper layers
can detect it correctly.

Signed-off-by: Matt Fornero <matt.fornero@mathworks.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 17ec4cee51dc..a47428b4d31b 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -310,8 +310,10 @@ static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
         ret = indio_dev->info->debugfs_reg_access(indio_dev,
                                                   indio_dev->cached_reg_addr,
                                                   0, &val);
-        if (ret)
+        if (ret) {
                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
+                return ret;
+        }
 
         len = snprintf(buf, sizeof(buf), "0x%X\n", val);