HID: hid-sensor-hub: Fix debug lock warning

When CONFIG_DEBUG_LOCK_ALLOC is defined, mutex magic is compared and
warned for (l->magic != l), here l is the address of mutex pointer.
In hid-sensor-hub as part of hsdev creation, a per hsdev mutex is
initialized during MFD cell creation. This hsdev, which contains, mutex
is part of platform data for the a cell. But platform_data is copied
in platform_device_add_data() in platform.c. This copy will copy the
whole hsdev structure including mutex. But once copied the magic
will no longer match. So when client driver call
sensor_hub_input_attr_get_raw_value, this will trigger mutex warning.
So to avoid this allocate mutex dynamically. This will be same even
after copy.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
index c3f6f1e311ea..090a1ba0abb6 100644
--- a/drivers/hid/hid-sensor-hub.c
+++ b/drivers/hid/hid-sensor-hub.c
@@ -294,7 +294,7 @@ int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
 	if (!report)
 		return -EINVAL;
 
-	mutex_lock(&hsdev->mutex);
+	mutex_lock(hsdev->mutex_ptr);
 	if (flag == SENSOR_HUB_SYNC) {
 		memset(&hsdev->pending, 0, sizeof(hsdev->pending));
 		init_completion(&hsdev->pending.ready);
@@ -328,7 +328,7 @@ int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
 		kfree(hsdev->pending.raw_data);
 		hsdev->pending.status = false;
 	}
-	mutex_unlock(&hsdev->mutex);
+	mutex_unlock(hsdev->mutex_ptr);
 
 	return ret_val;
 }
@@ -667,7 +667,14 @@ static int sensor_hub_probe(struct hid_device *hdev,
 			hsdev->vendor_id = hdev->vendor;
 			hsdev->product_id = hdev->product;
 			hsdev->usage = collection->usage;
-			mutex_init(&hsdev->mutex);
+			hsdev->mutex_ptr = devm_kzalloc(&hdev->dev,
+							sizeof(struct mutex),
+							GFP_KERNEL);
+			if (!hsdev->mutex_ptr) {
+				ret = -ENOMEM;
+				goto err_stop_hw;
+			}
+			mutex_init(hsdev->mutex_ptr);
 			hsdev->start_collection_index = i;
 			if (last_hsdev)
 				last_hsdev->end_collection_index = i;