Bluetooth: hci_sync: Set HCI_CMD_DRAIN_WORKQUEUE during device close

Since hci_dev_close_sync() can now be called during the reset path, we
should also set HCI_CMD_DRAIN_WORKQUEUE. This avoids queuing timeouts
while the hdev workqueue is being drained.

Fixes: 877afadad2 ("Bluetooth: When HCI work queue is drained, only queue chained work")
Signed-off-by: Heitor Alves de Siqueira <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>

net/bluetooth/hci_sync.c

@@ -5301,6 +5301,12 @@ int hci_dev_close_sync(struct hci_dev *hdev)
 
 	bt_dev_dbg(hdev, "");
 
+	/* Set HCI_DRAIN_WORKQUEUE flag to prevent queuing work during
+	 * reset/close. See hci_cmd_work() and handle_cmd_cnt_and_timer().
+	 */
+	hci_dev_set_flag(hdev, HCI_CMD_DRAIN_WORKQUEUE);
+	synchronize_rcu();
+
 	if (hci_dev_test_flag(hdev, HCI_UNREGISTER)) {
 		disable_delayed_work(&hdev->power_off);
 		disable_delayed_work(&hdev->ncmd_timer);
@@ -5324,6 +5330,7 @@ int hci_dev_close_sync(struct hci_dev *hdev)
 
 	if (!test_and_clear_bit(HCI_UP, &hdev->flags)) {
 		cancel_delayed_work_sync(&hdev->cmd_timer);
+		hci_dev_clear_flag(hdev, HCI_CMD_DRAIN_WORKQUEUE);
 		return err;
 	}
 
@@ -5423,6 +5430,7 @@ int hci_dev_close_sync(struct hci_dev *hdev)
 	/* Clear flags */
 	hdev->flags &= BIT(HCI_RAW);
 	hci_dev_clear_volatile_flags(hdev);
+	hci_dev_clear_flag(hdev, HCI_CMD_DRAIN_WORKQUEUE);
 
 	memset(hdev->eir, 0, sizeof(hdev->eir));
 	memset(hdev->dev_class, 0, sizeof(hdev->dev_class));