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 use mutex pointer, which points to the original
mutex structure, and use this. This will be same even after copy.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
drivers/hid/hid-sensor-hub.c | 5 +++--
include/linux/hid-sensor-hub.h | 2 ++
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
index 5eb338d..2ee6a3f8 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;
}
@@ -668,6 +668,7 @@ static int sensor_hub_probe(struct hid_device *hdev,
hsdev->product_id = hdev->product;
hsdev->usage = collection->usage;
mutex_init(&hsdev->mutex);
+ hsdev->mutex_ptr = &hsdev->mutex;
hsdev->start_collection_index = i;
if (last_hsdev)
last_hsdev->end_collection_index = i;
diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
index d48e91f..6f27c6e 100644
--- a/include/linux/hid-sensor-hub.h
+++ b/include/linux/hid-sensor-hub.h
@@ -75,6 +75,7 @@ struct sensor_hub_pending {
* @start_collection_index: Starting index for a phy type collection
* @end_collection_index: Last index for a phy type collection
* @mutex: synchronizing mutex.
+ * @mutex_ptr: Pointer to the above synchronizing mutex.
* @pending: Holds information of pending sync read request.
*/
struct hid_sensor_hub_device {
@@ -85,6 +86,7 @@ struct hid_sensor_hub_device {
int start_collection_index;
int end_collection_index;
struct mutex mutex;
+ struct mutex *mutex_ptr;
struct sensor_hub_pending pending;
};
--
2.1.0
--
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