[PATCH 4.9 105/107] power: generic-adc-battery: check for duplicate properties copied from iio channels

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>

commit a427503edaaed9b75ed9746a654cece7e93e60a8 upstream.

If an iio channel defines a basic property, there are duplicate entries
in /sys/class/power/*/uevent.

So add a check to avoid duplicates. Since all channels may be duplicates,
we have to modify the related error check.

Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: e60fea794e6e ("power: battery: Generic battery driver using IIO")
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/power/supply/generic-adc-battery.c |   15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

--- a/drivers/power/supply/generic-adc-battery.c
+++ b/drivers/power/supply/generic-adc-battery.c
@@ -246,6 +246,7 @@ static int gab_probe(struct platform_dev
 	int ret = 0;
 	int chan;
 	int index = ARRAY_SIZE(gab_props);
+	bool any = false;
 
 	adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
 	if (!adc_bat) {
@@ -292,12 +293,22 @@ static int gab_probe(struct platform_dev
 			adc_bat->channel[chan] = NULL;
 		} else {
 			/* copying properties for supported channels only */
-			psy_desc->properties[index++] = gab_dyn_props[chan];
+			int index2;
+
+			for (index2 = 0; index2 < index; index2++) {
+				if (psy_desc->properties[index2] ==
+				    gab_dyn_props[chan])
+					break;	/* already known */
+			}
+			if (index2 == index)	/* really new */
+				psy_desc->properties[index++] =
+					gab_dyn_props[chan];
+			any = true;
 		}
 	}
 
 	/* none of the channels are supported so let's bail out */
-	if (index == ARRAY_SIZE(gab_props)) {
+	if (!any) {
 		ret = -ENODEV;
 		goto second_mem_fail;
 	}