FAILED: patch "[PATCH] iio: hid-sensor-attributes: Fix sensor property setting" failed to apply to 4.9-stable tree

FAILED: patch "[PATCH] iio: hid-sensor-attributes: Fix sensor property setting" failed to apply to 4.9-stable tree

[gregkh]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From bba6d9e47f3ea894e501f94b086a59ffe28241ac Mon Sep 17 00:00:00 2001
From: Song Hongyan <hongyan.song@intel.com>
Date: Tue, 28 Mar 2017 22:23:55 +0800
Subject: [PATCH] iio: hid-sensor-attributes: Fix sensor property setting
 failure.

When system bootup without get sensor property, set sensor
property will be fail.

If no get_feature operation done before set_feature, the sensor
properties will all be the initialized value, which is not the
same with sensor real properties. When set sensor property it will
write back to sensor the changed perperty data combines with other
sensor properties data, it is not right and may be dangerous.

In order to get all sensor properties, choose to read one of the sensor
properties(no matter read any sensor peroperty, driver will get all
the peroperties and return the requested one).

Fixes: 73c6768b710a ("iio: hid-sensors: Common attribute and trigger")
Signed-off-by: Song Hongyan <hongyan.song@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
index 7afdac42ed42..01e02b9926d4 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
@@ -379,6 +379,8 @@ int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
 {
 
 	struct hid_sensor_hub_attribute_info timestamp;
+	s32 value;
+	int ret;
 
 	hid_sensor_get_reporting_interval(hsdev, usage_id, st);
 
@@ -417,6 +419,14 @@ int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
 		st->sensitivity.index, st->sensitivity.report_id,
 		timestamp.index, timestamp.report_id);
 
+	ret = sensor_hub_get_feature(hsdev,
+				st->power_state.report_id,
+				st->power_state.index, sizeof(value), &value);
+	if (ret < 0)
+		return ret;
+	if (value < 0)
+		return -EINVAL;
+
 	return 0;
 }
 EXPORT_SYMBOL(hid_sensor_parse_common_attributes);