Bluetooth: Introduce HCI_QUIRK_FIXUP_INQUIRY_MODE option

The HCI_QUIRK_FIXUP_INQUIRY_MODE option allows to force Inquiry Result
with RSSI setting on controllers that do not indicate support for it,
but where it is known to be fully functional.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/hci.h

@@ -102,6 +102,18 @@ enum {
 	 */
 	HCI_QUIRK_FIXUP_BUFFER_SIZE,
 
+	/* When this quirk is set, then a controller that does not
+	 * indicate support for Inquiry Result with RSSI is assumed to
+	 * support it anyway. Some early Bluetooth 1.2 controllers had
+	 * wrongly configured local features that will require forcing
+	 * them to enable this mode. Getting RSSI information with the
+	 * inquiry responses is preferred since it allows for a better
+	 * user expierence.
+	 *
+	 * This quirk must be set before hci_register_dev is called.
+	 */
+	HCI_QUIRK_FIXUP_INQUIRY_MODE,
+
 	/* When this quirk is set, then the HCI Read Local Supported
 	 * Commands command is not supported. In general Bluetooth 1.2
 	 * and later controllers should support this command. However

net/bluetooth/hci_core.c

@@ -621,7 +621,8 @@ static void hci_init2_req(struct hci_request *req, unsigned long opt)
 		}
 	}
 
-	if (lmp_inq_rssi_capable(hdev)) {
+	if (lmp_inq_rssi_capable(hdev) ||
+	    test_bit(HCI_QUIRK_FIXUP_INQUIRY_MODE, &hdev->quirks)) {
 		u8 mode;
 
 		/* If Extended Inquiry Result events are supported, then