Bluetooth: Fix advertising and active scanning co-existence

Many controllers allow simultaneous active scanning and advertising
(e.g. Intel and Broadcom) but some do not (e.g. CSR). It's therefore
safest to implement mutual exclusion of these states in the kernel.

This patch ensures that the two states are never entered simultaneously.
Extra precaution needs to be taken for outgoing connection attempts in
slave role (i.e. through directed advertising) in which case the
operation that came first has precedence and the one that comes after
gets a rejection.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 1517f1549f85..490ee8846d9e 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -772,6 +772,16 @@ struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
 
         /* If requested to connect as slave use directed advertising */
         if (!master) {
+                /* If we're active scanning most controllers are unable
+                 * to initiate advertising. Simply reject the attempt.
+                 */
+                if (test_bit(HCI_LE_SCAN, &hdev->dev_flags) &&
+                    hdev->le_scan_type == LE_SCAN_ACTIVE) {
+                        skb_queue_purge(&req.cmd_q);
+                        hci_conn_del(conn);
+                        return ERR_PTR(-EBUSY);
+                }
+
                 hci_req_directed_advertising(&req, conn);
                 goto create_conn;
         }