[PATCH 5.0 89/95] Bluetooth: Fix not initializing L2CAP tx_credits

Greg Kroah-Hartman
2019-05-09T18:53:39Z

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

commit ba8f5289f706aed94cc95b15cc5b89e22062f61f upstream.

l2cap_le_flowctl_init was reseting the tx_credits which works only for
outgoing connection since that set the tx_credits on the response, for
incoming connections that was not the case which leaves the channel
without any credits causing it to be suspended.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 4.20+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/bluetooth/l2cap_core.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -510,12 +510,12 @@ void l2cap_chan_set_defaults(struct l2ca
}
EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults);

-static void l2cap_le_flowctl_init(struct l2cap_chan *chan)
+static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits)
{
chan->sdu = NULL;
chan->sdu_last_frag = NULL;
chan->sdu_len = 0;
- chan->tx_credits = 0;
+ chan->tx_credits = tx_credits;
/* Derive MPS from connection MTU to stop HCI fragmentation */
chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE);
/* Give enough credits for a full packet */
@@ -1281,7 +1281,7 @@ static void l2cap_le_connect(struct l2ca
if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags))
return;

- l2cap_le_flowctl_init(chan);
+ l2cap_le_flowctl_init(chan, 0);

req.psm = chan->psm;
req.scid = cpu_to_le16(chan->scid);
@@ -5531,11 +5531,10 @@ static int l2cap_le_connect_req(struct l
chan->dcid = scid;
chan->omtu = mtu;
chan->remote_mps = mps;
- chan->tx_credits = __le16_to_cpu(req->credits);

__l2cap_chan_add(conn, chan);

- l2cap_le_flowctl_init(chan);
+ l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits));

dcid = chan->scid;
credits = chan->rx_credits;