[PATCH 5.15 269/530] iio: inkern: fix return value in devm_of_iio_channel_get_by_name()

[Greg Kroah-Hartman]

From: Nuno Sá <nuno.sa@xxxxxxxxxx>

[ Upstream commit 9e878dbc0e8322f8b2f5ab0093c1e89926362dbe ]

of_iio_channel_get_by_name() can either return NULL or an error pointer
so that only doing IS_ERR() is not enough. Fix it by checking the NULL
pointer case and return -ENODEV in that case. Note this is done like this
so that users of the function (which only check for error pointers) do
not need to be changed. This is not ideal since we are losing error codes
and as such, in a follow up change, things will be unified so that
of_iio_channel_get_by_name() only returns error codes.

Fixes: 6e39b145cef7 ("iio: provide of_iio_channel_get_by_name() and devm_ version it")
Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220715122903.332535-3-nuno.sa@xxxxxxxxxx
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/iio/inkern.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 30a8ecb692f8..bf9ce01c854b 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -395,6 +395,8 @@ struct iio_channel *devm_of_iio_channel_get_by_name(struct device *dev,
 	channel = of_iio_channel_get_by_name(np, channel_name);
 	if (IS_ERR(channel))
 		return channel;
+	if (!channel)
+		return ERR_PTR(-ENODEV);
 
 	ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
 	if (ret)
-- 
2.35.1