Bluetooth: Fix ACL MTU issue

ERTM and Streaming Modes was having problems when the ACL MTU is lower
than MPS. The 'minus 10' is to take in account the header and fcs
lenghts.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Reviewed-by: João Paulo Rechi Vita <jprvita@profusion.mobi>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 401011a53c73..99cf1772b481 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -2267,6 +2267,8 @@ done:
                 rfc.retrans_timeout = 0;
                 rfc.monitor_timeout = 0;
                 rfc.max_pdu_size    = cpu_to_le16(L2CAP_DEFAULT_MAX_PDU_SIZE);
+                if (L2CAP_DEFAULT_MAX_PDU_SIZE > pi->conn->mtu - 10)
+                        rfc.max_pdu_size = pi->conn->mtu - 10;
 
                 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
                                         sizeof(rfc), (unsigned long) &rfc);
@@ -2288,6 +2290,8 @@ done:
                 rfc.retrans_timeout = 0;
                 rfc.monitor_timeout = 0;
                 rfc.max_pdu_size    = cpu_to_le16(L2CAP_DEFAULT_MAX_PDU_SIZE);
+                if (L2CAP_DEFAULT_MAX_PDU_SIZE > pi->conn->mtu - 10)
+                        rfc.max_pdu_size = pi->conn->mtu - 10;
 
                 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
                                         sizeof(rfc), (unsigned long) &rfc);