commit c17747546d0024ef34083377e0645943131b31e4
author Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Fri Jul 08 14:51:44 2016 +0300
committer Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Wed Jul 13 14:03:45 2016 +0300
tree 12e046c13f66235a2d6d8fb3bd3d5252d31fdfe1
parent 05bdde05b2176b42f6334c4f478395cfc6943abf

shared/gatt-client: Don't use exchange MTU with BR/EDR links

Accourding to the spec MTU should ne negotiated using L2CAP channel
configuration procedures:

BLUETOOTH SPECIFICATION Version 4.2 [Vol 3, Part G] page 546:

  4.3.1 Exchange MTU

  This sub-procedure shall not be used on a BR/EDR physical link since
  the MTU size is negotiated using L2CAP channel configuration
  procedures.

src/shared/gatt-client.c

diff --git a/src/shared/gatt-client.c b/src/shared/gatt-client.c
index adabfe3..8fd8a45 100644
--- a/src/shared/gatt-client.c
+++ b/src/shared/gatt-client.c
@@ -1622,14 +1622,25 @@
 	if (!op)
 		return false;
 
+	/*
+	 * BLUETOOTH SPECIFICATION Version 4.2 [Vol 3, Part G] page 546:
+	 *
+	 * 4.3.1 Exchange MTU
+	 *
+	 * This sub-procedure shall not be used on a BR/EDR physical link since
+	 * the MTU size is negotiated using L2CAP channel configuration
+	 * procedures.
+	 */
+	if (bt_att_get_link_type(client->att) == BT_ATT_LINK_BREDR)
+		goto discover;
+
 	/* Check if MTU needs to be send */
 	mtu = MAX(BT_ATT_DEFAULT_LE_MTU, mtu);
 	if (mtu == BT_ATT_DEFAULT_LE_MTU)
 		goto discover;
 
 	/* Configure the MTU */
-	client->mtu_req_id = bt_gatt_exchange_mtu(client->att,
-						MAX(BT_ATT_DEFAULT_LE_MTU, mtu),
+	client->mtu_req_id = bt_gatt_exchange_mtu(client->att, mtu,
 						exchange_mtu_cb,
 						discovery_op_ref(op),
 						discovery_op_unref);