Bluetooth: Add SCO fallback for eSCO connection attempts

When attempting to setup eSCO connections it can happen that some link
manager implementations fail to properly negotiate the eSCO parameters
and thus fail the eSCO setup. Normally the link manager is responsible
for the negotiation of the parameters and actually fallback to SCO if
no agreement can be reached. In cases where the link manager is just too
stupid, then at least try to establish a SCO link if eSCO fails.

For the Bluetooth devices with EDR support this includes handling packet
types of EDR basebands. This is particular tricky since for the EDR the
logic of enabling/disabling one specific packet type is turned around.
This fix contains an extra bitmask to disable eSCO EDR packet when
trying to fallback to a SCO connection.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 3645139..f69f015 100644 (file)
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -133,8 +133,13 @@ enum {
 #define ESCO_EV3       0x0008
 #define ESCO_EV4       0x0010
 #define ESCO_EV5       0x0020
+#define ESCO_2EV3      0x0040
+#define ESCO_3EV3      0x0080
+#define ESCO_2EV5      0x0100
+#define ESCO_3EV5      0x0200
 
 #define SCO_ESCO_MASK  (ESCO_HV1 | ESCO_HV2 | ESCO_HV3)
+#define EDR_ESCO_MASK  (ESCO_2EV3 | ESCO_3EV3 | ESCO_2EV5 | ESCO_3EV5)
 
 /* ACL flags */
 #define ACL_CONT               0x01
@@ -176,6 +181,9 @@ enum {
 #define LMP_EV5                0x02
 
 #define LMP_SNIFF_SUBR 0x02
+#define LMP_EDR_ESCO_2M        0x20
+#define LMP_EDR_ESCO_3M        0x40
+#define LMP_EDR_3S_ESCO        0x80
 
 #define LMP_SIMPLE_PAIR        0x08
 

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 98f97a1..2435e83 100644 (file)
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -123,6 +123,8 @@ void hci_add_sco(struct hci_conn *conn, __u16 handle)
        conn->state = BT_CONNECT;
        conn->out = 1;
 
+       conn->attempt++;
+
        cp.handle   = cpu_to_le16(handle);
        cp.pkt_type = cpu_to_le16(conn->pkt_type);
 
@@ -139,6 +141,8 @@ void hci_setup_sync(struct hci_conn *conn, __u16 handle)
        conn->state = BT_CONNECT;
        conn->out = 1;
 
+       conn->attempt++;
+
        cp.handle   = cpu_to_le16(handle);
        cp.pkt_type = cpu_to_le16(conn->pkt_type);
 
@@ -216,12 +220,13 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
                break;
        case SCO_LINK:
                if (lmp_esco_capable(hdev))
-                       conn->pkt_type = hdev->esco_type & SCO_ESCO_MASK;
+                       conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
+                                       (hdev->esco_type & EDR_ESCO_MASK);
                else
                        conn->pkt_type = hdev->pkt_type & SCO_PTYPE_MASK;
                break;
        case ESCO_LINK:
-               conn->pkt_type = hdev->esco_type;
+               conn->pkt_type = hdev->esco_type & ~EDR_ESCO_MASK;
                break;
        }
 

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 014fc8b..899b899 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -484,6 +484,15 @@ static void hci_cc_read_local_features(struct hci_dev *hdev, struct sk_buff *skb
        if (hdev->features[4] & LMP_EV5)
                hdev->esco_type |= (ESCO_EV5);
 
+       if (hdev->features[5] & LMP_EDR_ESCO_2M)
+               hdev->esco_type |= (ESCO_2EV3);
+
+       if (hdev->features[5] & LMP_EDR_ESCO_3M)
+               hdev->esco_type |= (ESCO_3EV3);
+
+       if (hdev->features[5] & LMP_EDR_3S_ESCO)
+               hdev->esco_type |= (ESCO_2EV5 | ESCO_3EV5);
+
        BT_DBG("%s features 0x%.2x%.2x%.2x%.2x%.2x%.2x%.2x%.2x", hdev->name,
                                        hdev->features[0], hdev->features[1],
                                        hdev->features[2], hdev->features[3],
@@ -1639,6 +1648,13 @@ static inline void hci_sync_conn_complete_evt(struct hci_dev *hdev, struct sk_bu
                conn->type = SCO_LINK;
        }
 
+       if (conn->out && ev->status == 0x1c && conn->attempt < 2) {
+               conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
+                                       (hdev->esco_type & EDR_ESCO_MASK);
+               hci_setup_sync(conn, conn->link->handle);
+               goto unlock;
+       }
+
        if (!ev->status) {
                conn->handle = __le16_to_cpu(ev->handle);
                conn->state  = BT_CONNECTED;