FROMGIT: Bluetooth: use the proper scan params when conn is pending

When an LE connection is requested and an RPA update is needed via
hci_connect_le_scan, the default scanning parameters are used rather
than the connect parameters.  This leads to significant delays in the
connection establishment process when using lower duty cycle scanning
parameters.

The patch simply looks at the pended connection list when trying to
determine which scanning parameters should be used.

Before:
< HCI Command: LE Set Extended Scan Parameters (0x08|0x0041) plen 8
                            torvalds#378 [hci0] 1659.247156
        Own address type: Public (0x00)
        Filter policy: Ignore not in white list (0x01)
        PHYs: 0x01
        Entry 0: LE 1M
          Type: Passive (0x00)
          Interval: 367.500 msec (0x024c)
          Window: 37.500 msec (0x003c)

After:
< HCI Command: LE Set Extended Scan Parameters (0x08|0x0041) plen 8
                               torvalds#39 [hci0] 7.422109
        Own address type: Public (0x00)
        Filter policy: Ignore not in white list (0x01)
        PHYs: 0x01
        Entry 0: LE 1M
          Type: Passive (0x00)
          Interval: 60.000 msec (0x0060)
          Window: 60.000 msec (0x0060)

Signed-off-by: Alain Michaud <alainm@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Yu Liu <yudiliu@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

(cherry picked from commit 9a9373f
git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git
master)

BUG=b:162529117
TEST=Open the network systray UI and validate the appropriate scanning
parameters are used.

Signed-off-by: Alain Michaud <alainm@chromium.org>
Change-Id: I16bd8b336329e61ae70cf41e83623266bbb99c9c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2330531
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Yu Liu <yudiliu@google.com>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

net/bluetooth/hci_request.c

@@ -911,6 +911,27 @@ static void hci_req_start_scan(struct hci_request *req, u8 type, u16 interval,
 	}
 }
 
+/* Returns true if an le connection is in the scanning state */
+static inline bool hci_is_le_conn_scanning(struct hci_dev *hdev)
+{
+	struct hci_conn_hash *h = &hdev->conn_hash;
+	struct hci_conn  *c;
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(c, &h->list, list) {
+		if (c->type == LE_LINK && c->state == BT_CONNECT &&
+		    test_bit(HCI_CONN_SCANNING, &c->flags)) {
+			rcu_read_unlock();
+			return true;
+		}
+	}
+
+	rcu_read_unlock();
+
+	return false;
+}
+
 void hci_req_add_le_passive_scan(struct hci_request *req)
 {
 	struct hci_dev *hdev = req->hdev;
@@ -955,6 +976,9 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
 	if (hdev->suspended) {
 		window = hdev->le_scan_window_suspend;
 		interval = hdev->le_scan_int_suspend;
+	} else if (hci_is_le_conn_scanning(hdev)) {
+		window = hdev->le_scan_window_connect;
+		interval = hdev->le_scan_int_connect;
 	} else {
 		window = hdev->le_scan_window;
 		interval = hdev->le_scan_interval;