net/ixgbe: fix link up in FreeBSD

In FreeBSD environment, nic_uio drivers do not support interrupts,
rte_intr_callback_register() will fail to register interrupts.
We cannot make link status to change from down to up by interrupt
callback. So we need to wait for the controller to acquire link
when ports start. Through multiple tests, 5s should be enough.

Fixes: b9bd0f0 ("ethdev: fix link status query")
Cc: stable@dpdk.org

Signed-off-by: Lunyuan Cui <lunyuanx.cui@intel.com>
Acked-by: Xiaolong Ye <xiaolong.ye@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

drivers/net/ixgbe/ixgbe_ethdev.c

@@ -378,6 +378,7 @@ static int ixgbe_dev_udp_tunnel_port_del(struct rte_eth_dev *dev,
 					 struct rte_eth_udp_tunnel *udp_tunnel);
 static int ixgbe_filter_restore(struct rte_eth_dev *dev);
 static void ixgbe_l2_tunnel_conf(struct rte_eth_dev *dev);
+static int ixgbe_wait_for_link_up(struct ixgbe_hw *hw);
 
 /*
  * Define VF Stats MACRO for Non "cleared on read" register
@@ -2801,6 +2802,11 @@ ixgbe_dev_start(struct rte_eth_dev *dev)
 			    "please call hierarchy_commit() "
 			    "before starting the port");
 
+	/* wait for the controller to acquire link */
+	err = ixgbe_wait_for_link_up(hw);
+	if (err)
+		goto error;
+
 	/*
 	 * Update link status right before return, because it may
 	 * start link configuration process in a separate thread.
@@ -4114,6 +4120,36 @@ ixgbe_dev_setup_link_alarm_handler(void *param)
 	intr->flags &= ~IXGBE_FLAG_NEED_LINK_CONFIG;
 }
 
+/*
+ * In freebsd environment, nic_uio drivers do not support interrupts,
+ * rte_intr_callback_register() will fail to register interrupts.
+ * We can not make link status to change from down to up by interrupt
+ * callback. So we need to wait for the controller to acquire link
+ * when ports start.
+ * It returns 0 on link up.
+ */
+static int
+ixgbe_wait_for_link_up(struct ixgbe_hw *hw)
+{
+#ifdef RTE_EXEC_ENV_FREEBSD
+	const int nb_iter = 25;
+#else
+	const int nb_iter = 0;
+#endif
+	int err, i, link_up = 0;
+	uint32_t speed = 0;
+
+	for (i = 0; i < nb_iter; i++) {
+		err = ixgbe_check_link(hw, &speed, &link_up, 0);
+		if (err)
+			return err;
+		if (link_up)
+			return 0;
+		msec_delay(200);
+	}
+	return 0;
+}
+
 /* return 0 means link status changed, -1 means not changed */
 int
 ixgbe_dev_link_update_share(struct rte_eth_dev *dev,