Bluetooth: Check for SCO type before setting retransmission effort

SCO connection cannot be setup to devices that do not support retransmission.
Patch based on http://permalink.gmane.org/gmane.linux.bluez.kernel/7779 and
adapted for this kernel version.

Code changed to check SCO/eSCO type before setting retransmission effort
and max. latency. The purpose of the patch is to support older devices not
capable of eSCO.

Tested on Blackberry 655+ headset which does not support retransmission.
Credits go to Alexander Sommerhuber.

Signed-off-by: Bernhard Thaler <bernhard.thaler@r-it.at>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_conn.c

@@ -38,14 +38,19 @@ struct sco_param {
 	u16 max_latency;
 };
 
-static const struct sco_param sco_param_cvsd[] = {
+static const struct sco_param esco_param_cvsd[] = {
 	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x000a }, /* S3 */
 	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x0007 }, /* S2 */
 	{ EDR_ESCO_MASK | ESCO_EV3,   0x0007 }, /* S1 */
 	{ EDR_ESCO_MASK | ESCO_HV3,   0xffff }, /* D1 */
 	{ EDR_ESCO_MASK | ESCO_HV1,   0xffff }, /* D0 */
 };
 
+static const struct sco_param sco_param_cvsd[] = {
+	{ EDR_ESCO_MASK | ESCO_HV3,   0xffff }, /* D1 */
+	{ EDR_ESCO_MASK | ESCO_HV1,   0xffff }, /* D0 */
+};
+
 static const struct sco_param sco_param_wideband[] = {
 	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x000d }, /* T2 */
 	{ EDR_ESCO_MASK | ESCO_EV3,   0x0008 }, /* T1 */
@@ -207,10 +212,17 @@ bool hci_setup_sync(struct hci_conn *conn, __u16 handle)
 		param = &sco_param_wideband[conn->attempt - 1];
 		break;
 	case SCO_AIRMODE_CVSD:
-		if (conn->attempt > ARRAY_SIZE(sco_param_cvsd))
-			return false;
-		cp.retrans_effort = 0x01;
-		param = &sco_param_cvsd[conn->attempt - 1];
+		if (lmp_esco_capable(conn->link)) {
+			if (conn->attempt > ARRAY_SIZE(esco_param_cvsd))
+				return false;
+			cp.retrans_effort = 0x01;
+			param = &esco_param_cvsd[conn->attempt - 1];
+		} else {
+			if (conn->attempt > ARRAY_SIZE(sco_param_cvsd))
+				return false;
+			cp.retrans_effort = 0xff;
+			param = &sco_param_cvsd[conn->attempt - 1];
+		}
 		break;
 	default:
 		return false;