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>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 3645139e68c7..f69f015bbcc0 100644
--- 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