net/hns3: fix flow control exception

[ upstream commit f1c5552 ]

In multi-TC scenarios, MAC pause is not supported. Otherwise, only
TC0 can trigger pause frames, and other TCs cannot trigger pause
frames. In this case, flow control does not meet the expectation.

Fixes: 62e3ccc ("net/hns3: support flow control")

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Min Hu (Connor) <humin29@huawei.com>

drivers/net/hns3/hns3_ethdev.c

@@ -5279,6 +5279,11 @@ hns3_flow_ctrl_set(struct rte_eth_dev *dev, struct rte_eth_fc_conf *fc_conf)
 		return -EOPNOTSUPP;
 	}
 
+	if (hw->num_tc > 1) {
+		hns3_err(hw, "in multi-TC scenarios, MAC pause is not supported.");
+		return -EOPNOTSUPP;
+	}
+
 	hns3_get_fc_mode(hw, fc_conf->mode);
 	if (hw->requested_mode == hw->current_mode &&
 	    pf->pause_time == fc_conf->pause_time)