HID: sensor-hub: make dyn_callback_lock IRQ-safe

dyn_callback_lock is being taken from IRQ context through hid_irq_in() ->
hid_input_report() -> sensor_hub_raw_event() -> sensor_hub_get_callback(),
therefore anyone else acquiring it needs to disable IRQs to disable deadlocks.
Reported-by: NAlexander Holler <holler@ahsoftware.de>
Tested-by: NAlexander Holler <holler@ahsoftware.de>
Reported-by: NReyad Attiyat <reyad.attiyat@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

drivers/hid/hid-sensor-hub.c

@@ -159,17 +159,18 @@ int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
 {
 	struct hid_sensor_hub_callbacks_list *callback;
 	struct sensor_hub_data *pdata = hid_get_drvdata(hsdev->hdev);
+	unsigned long flags;
 
-	spin_lock(&pdata->dyn_callback_lock);
+	spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
 	list_for_each_entry(callback, &pdata->dyn_callback_list, list)
 		if (callback->usage_id == usage_id &&
 						callback->hsdev == hsdev) {
-			spin_unlock(&pdata->dyn_callback_lock);
+			spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
 			return -EINVAL;
 		}
 	callback = kzalloc(sizeof(*callback), GFP_ATOMIC);
 	if (!callback) {
-		spin_unlock(&pdata->dyn_callback_lock);
+		spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
 		return -ENOMEM;
 	}
 	callback->hsdev = hsdev;
@@ -177,7 +178,7 @@ int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
 	callback->usage_id = usage_id;
 	callback->priv = NULL;
 	list_add_tail(&callback->list, &pdata->dyn_callback_list);
-	spin_unlock(&pdata->dyn_callback_lock);
+	spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
 
 	return 0;
 }
@@ -188,8 +189,9 @@ int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
 {
 	struct hid_sensor_hub_callbacks_list *callback;
 	struct sensor_hub_data *pdata = hid_get_drvdata(hsdev->hdev);
+	unsigned long flags;
 
-	spin_lock(&pdata->dyn_callback_lock);
+	spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
 	list_for_each_entry(callback, &pdata->dyn_callback_list, list)
 		if (callback->usage_id == usage_id &&
 						callback->hsdev == hsdev) {
@@ -197,7 +199,7 @@ int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
 			kfree(callback);
 			break;
 		}
-	spin_unlock(&pdata->dyn_callback_lock);
+	spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
 
 	return 0;
 }
@@ -378,15 +380,16 @@ static int sensor_hub_suspend(struct hid_device *hdev, pm_message_t message)
 {
 	struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
 	struct hid_sensor_hub_callbacks_list *callback;
+	unsigned long flags;
 
 	hid_dbg(hdev, " sensor_hub_suspend\n");
-	spin_lock(&pdata->dyn_callback_lock);
+	spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
 	list_for_each_entry(callback, &pdata->dyn_callback_list, list) {
 		if (callback->usage_callback->suspend)
 			callback->usage_callback->suspend(
 					callback->hsdev, callback->priv);
 	}
-	spin_unlock(&pdata->dyn_callback_lock);
+	spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
 
 	return 0;
 }
@@ -395,15 +398,16 @@ static int sensor_hub_resume(struct hid_device *hdev)
 {
 	struct sensor_hub_data *pdata = hid_get_drvdata(hdev);
 	struct hid_sensor_hub_callbacks_list *callback;
+	unsigned long flags;
 
 	hid_dbg(hdev, " sensor_hub_resume\n");
-	spin_lock(&pdata->dyn_callback_lock);
+	spin_lock_irqsave(&pdata->dyn_callback_lock, flags);
 	list_for_each_entry(callback, &pdata->dyn_callback_list, list) {
 		if (callback->usage_callback->resume)
 			callback->usage_callback->resume(
 					callback->hsdev, callback->priv);
 	}
-	spin_unlock(&pdata->dyn_callback_lock);
+	spin_unlock_irqrestore(&pdata->dyn_callback_lock, flags);
 
 	return 0;
 }