Bluetooth: Run page scan updates through hdev->req_workqueue
Since Add/Remove Device perform the page scan updates independently
from the HCI command completion we've introduced a potential race when
multiple mgmt commands are queued. Doing the page scan updates through
the req_workqueue ensures that the state changes are performed in a
race-free manner.
At the same time, to make the request helper more widely usable,
extend it to also cover Inquiry Scan changes since those are behind
the same HCI command. This is also reflected in the new name of the
API as well as the work struct name.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index e639671..78c026b 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -637,7 +637,7 @@
return false;
}
-void __hci_update_page_scan(struct hci_request *req)
+void __hci_req_update_scan(struct hci_request *req)
{
struct hci_dev *hdev = req->hdev;
u8 scan;
@@ -657,22 +657,29 @@
else
scan = SCAN_DISABLED;
- if (test_bit(HCI_PSCAN, &hdev->flags) == !!(scan & SCAN_PAGE))
- return;
-
if (hci_dev_test_flag(hdev, HCI_DISCOVERABLE))
scan |= SCAN_INQUIRY;
+ if (test_bit(HCI_PSCAN, &hdev->flags) == !!(scan & SCAN_PAGE) &&
+ test_bit(HCI_ISCAN, &hdev->flags) == !!(scan & SCAN_INQUIRY))
+ return;
+
hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan);
}
-void hci_update_page_scan(struct hci_dev *hdev)
+static int update_scan(struct hci_request *req, unsigned long opt)
{
- struct hci_request req;
+ hci_dev_lock(req->hdev);
+ __hci_req_update_scan(req);
+ hci_dev_unlock(req->hdev);
+ return 0;
+}
- hci_req_init(&req, hdev);
- __hci_update_page_scan(&req);
- hci_req_run(&req, NULL);
+static void scan_update_work(struct work_struct *work)
+{
+ struct hci_dev *hdev = container_of(work, struct hci_dev, scan_update);
+
+ hci_req_sync(hdev, update_scan, 0, HCI_CMD_TIMEOUT, NULL);
}
/* This function controls the background scanning based on hdev->pend_le_conns
@@ -1270,6 +1277,7 @@
{
INIT_WORK(&hdev->discov_update, discov_update);
INIT_WORK(&hdev->bg_scan_update, bg_scan_update);
+ INIT_WORK(&hdev->scan_update, scan_update_work);
INIT_DELAYED_WORK(&hdev->le_scan_disable, le_scan_disable_work);
INIT_DELAYED_WORK(&hdev->le_scan_restart, le_scan_restart_work);
}
@@ -1280,6 +1288,7 @@
cancel_work_sync(&hdev->discov_update);
cancel_work_sync(&hdev->bg_scan_update);
+ cancel_work_sync(&hdev->scan_update);
cancel_delayed_work_sync(&hdev->le_scan_disable);
cancel_delayed_work_sync(&hdev->le_scan_restart);
}