Bluetooth: host: Fix L2CAP reconfigure response with invalid MTU

sjanc · cfriedt · commit 089675af45e3 · 2022-08-02T12:36:44.000-04:00
TSE18813 clarified IUT behavior and rejecting reconfiguration which would result in MTU decrease is enough. There is no need to disconnect L2CAP channel(s). This was affecting L2CAP/ECFC/BI-03-C qualification test case (TCRL 2022-2). Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl> (cherry picked from commit 266394d)
diff --git a/subsys/bluetooth/host/l2cap.c b/subsys/bluetooth/host/l2cap.c
@@ -1298,15 +1298,10 @@ static void le_ecred_reconf_req(struct bt_l2cap *l2cap, uint8_t ident,
 			continue;
 		}
 
-		/* If the MTU value is decreased for any of the included
-		 * channels, then the receiver shall disconnect all
-		 * included channels.
-		 */
 		if (BT_L2CAP_LE_CHAN(chan)->tx.mtu > mtu) {
 			BT_ERR("chan %p decreased MTU %u -> %u", chan,
 			       BT_L2CAP_LE_CHAN(chan)->tx.mtu, mtu);
 			result = BT_L2CAP_RECONF_INVALID_MTU;
-			bt_l2cap_chan_disconnect(chan);
 			goto response;
 		}
 

Original file line number	Diff line number	Diff line change
`@@ -1298,15 +1298,10 @@ static void le_ecred_reconf_req(struct bt_l2cap *l2cap, uint8_t ident,`
`1298`	`1298`	`continue;`
`1299`	`1299`	`}`
`1300`	`1300`
`1301`		`- /* If the MTU value is decreased for any of the included`
`1302`		`- * channels, then the receiver shall disconnect all`
`1303`		`- * included channels.`
`1304`		`- */`
`1305`	`1301`	`if (BT_L2CAP_LE_CHAN(chan)->tx.mtu > mtu) {`
`1306`	`1302`	`BT_ERR("chan %p decreased MTU %u -> %u", chan,`
`1307`	`1303`	`BT_L2CAP_LE_CHAN(chan)->tx.mtu, mtu);`
`1308`	`1304`	`result = BT_L2CAP_RECONF_INVALID_MTU;`
`1309`		`- bt_l2cap_chan_disconnect(chan);`
`1310`	`1305`	`goto response;`
`1311`	`1306`	`}`
`1312`	`1307`