[PATCH 3/3] hwmon: iio_hwmon: defer probe when no channel is found

Quentin Schulz quentin.schulz at free-electrons.com
Tue Jun 28 01:18:17 PDT 2016

iio_channel_get_all returns -ENODEV when it cannot find either phandles and
properties in the Device Tree or channels whose consumer_dev_name matches
iio_hwmon in iio_map_list. The iio_map_list is filled in by iio drivers
which might be probed after iio_hwmon.

It is better to defer the probe of iio_hwmon if such error is returned by
iio_channel_get_all in order to let a chance to iio drivers to expose
channels in iio_map_list.

Signed-off-by: Quentin Schulz <quentin.schulz at free-electrons.com>
 drivers/hwmon/iio_hwmon.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/iio_hwmon.c b/drivers/hwmon/iio_hwmon.c
index b550ba5..c0da4d9 100644
--- a/drivers/hwmon/iio_hwmon.c
+++ b/drivers/hwmon/iio_hwmon.c
@@ -73,8 +73,11 @@ static int iio_hwmon_probe(struct platform_device *pdev)
 		name = dev->of_node->name;
 	channels = iio_channel_get_all(dev);
-	if (IS_ERR(channels))
+	if (IS_ERR(channels)) {
+		if (PTR_ERR(channels) == -ENODEV)
+			return -EPROBE_DEFER;
 		return PTR_ERR(channels);
+	}
 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
 	if (st == NULL) {

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