[RFC] Bluetooth: hci_sync: Fix not processing all entries on cmd_sync_work

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

The could be multiple hci_cmd_sync_work_entry enqueued when
hci_cmd_sync_work is executed so this makes sure they are all
dequeued properly.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/hci_sync.c | 65 ++++++++++++++++++++++++----------------
 1 file changed, 39 insertions(+), 26 deletions(-)

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index d146d4efae43..724d34bdd62a 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -273,43 +273,56 @@ int __hci_cmd_sync_status(struct hci_dev *hdev, u16 opcode, u32 plen,
 }
 EXPORT_SYMBOL(__hci_cmd_sync_status);
 
-static void hci_cmd_sync_work(struct work_struct *work)
+
+static void hci_cmd_sync_work_entry_run(struct hci_dev *hdev,
+					struct hci_cmd_sync_work_entry *entry)
 {
-	struct hci_dev *hdev = container_of(work, struct hci_dev, cmd_sync_work);
-	struct hci_cmd_sync_work_entry *entry;
 	hci_cmd_sync_work_func_t func;
 	hci_cmd_sync_work_destroy_t destroy;
 	void *data;
+	int err;
 
-	bt_dev_dbg(hdev, "");
+	bt_dev_dbg(hdev, "entry %p", entry);
 
-	mutex_lock(&hdev->cmd_sync_work_lock);
-	entry = list_first_entry(&hdev->cmd_sync_work_list,
-				 struct hci_cmd_sync_work_entry, list);
-	if (entry) {
-		list_del(&entry->list);
-		func = entry->func;
-		data = entry->data;
-		destroy = entry->destroy;
-		kfree(entry);
-	} else {
-		func = NULL;
-		data = NULL;
-		destroy = NULL;
-	}
-	mutex_unlock(&hdev->cmd_sync_work_lock);
+	func = entry->func;
+	data = entry->data;
+	destroy = entry->destroy;
+	kfree(entry);
 
-	if (func) {
-		int err;
+	if (!func)
+		return;
+
+	hci_req_sync_lock(hdev);
+
+	err = func(hdev, data);
 
-		hci_req_sync_lock(hdev);
+	if (destroy)
+		destroy(hdev, data, err);
 
-		err = func(hdev, data);
+	hci_req_sync_unlock(hdev);
+}
 
-		if (destroy)
-			destroy(hdev, data, err);
+static void hci_cmd_sync_work(struct work_struct *work)
+{
+	struct hci_dev *hdev = container_of(work, struct hci_dev, cmd_sync_work);
+	struct hci_cmd_sync_work_entry *entry;
+
+	bt_dev_dbg(hdev, "");
+
+	while (1) {
+		mutex_lock(&hdev->cmd_sync_work_lock);
+		entry = list_first_entry_or_null(&hdev->cmd_sync_work_list,
+						 struct hci_cmd_sync_work_entry,
+						 list);
+		if (!entry) {
+			mutex_unlock(&hdev->cmd_sync_work_lock);
+			break;
+		}
+
+		list_del(&entry->list);
+		mutex_unlock(&hdev->cmd_sync_work_lock);
 
-		hci_req_sync_unlock(hdev);
+		hci_cmd_sync_work_entry_run(hdev, entry);
 	}
 }
 
-- 
2.35.1