net: hns3: reallocate SSU' buffer size when pfc_en changes

When a TC's PFC is disabled or enabled, the RX private buffer for
this TC need to be changed too, otherwise this may cause packet
dropped problem.

This patch fixes it by calling hclge_buffer_alloc to reallocate
buffer when pfc_en changes.

Fixes: cacde272 ("net: hns3: Add hclge_dcb module for the support of DCB feature")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_dcb.c

@@ -318,6 +318,7 @@ static int hclge_ieee_setpfc(struct hnae3_handle *h, struct ieee_pfc *pfc)
 	struct net_device *netdev = h->kinfo.netdev;
 	struct hclge_dev *hdev = vport->back;
 	u8 i, j, pfc_map, *prio_tc;
+	int ret;
 
 	if (!(hdev->dcbx_cap & DCB_CAP_DCBX_VER_IEEE) ||
 	    hdev->flag & HCLGE_FLAG_MQPRIO_ENABLE)
@@ -347,7 +348,21 @@ static int hclge_ieee_setpfc(struct hnae3_handle *h, struct ieee_pfc *pfc)
 
 	hclge_tm_pfc_info_update(hdev);
 
-	return hclge_pause_setup_hw(hdev, false);
+	ret = hclge_pause_setup_hw(hdev, false);
+	if (ret)
+		return ret;
+
+	ret = hclge_notify_client(hdev, HNAE3_DOWN_CLIENT);
+	if (ret)
+		return ret;
+
+	ret = hclge_buffer_alloc(hdev);
+	if (ret) {
+		hclge_notify_client(hdev, HNAE3_UP_CLIENT);
+		return ret;
+	}
+
+	return hclge_notify_client(hdev, HNAE3_UP_CLIENT);
 }
 
 /* DCBX configuration */