[PATCH 1/1] bonding: delay up state without speed and duplex in 802.3ad mode

[<zyjzyj2000@gmail.com>]

From: yzhu1 <yzhu1@windriver.com>

In 802.3ad mode, the speed and duplex is needed. But in some NICs,
there is a time span between NIC up state and getting speed and duplex.
As such, sometimes a slave in 802.3ad mode is in up state without
speed and duplex. This will make bonding in 802.3ad mode can not
work well.

To make bonding driver robust and compatible with more NICs, it is
necessary to delay the up state without speed and duplex in 802.3ad
mode.

Signed-off-by: yzhu1 <yzhu1@windriver.com>
---
 drivers/net/bonding/bond_main.c |   34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 9e0f8a7..a1d8708 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -419,6 +419,35 @@ const char *bond_slave_link_status(s8 link)
 	}
 }
 
+/* This function is to check the speed and duplex of a NIC.
+ * Since the speed and duplex of a slave device are very
+ * important to the bonding in the 802.3ad mode. As such,
+ * it is necessary to check the speed and duplex of a slave
+ * device in 802.3ad mode.
+ *
+ * speed != SPEED_UNKNOWN and duplex == DUPLEX_FULL  :  1
+ *                                           others  :  0
+ */
+static int __check_speed_duplex(struct net_device *netdev)
+{
+	struct ethtool_cmd ecmd;
+	u32 slave_speed = SPEED_UNKNOWN;
+	int res;
+
+	res = __ethtool_get_settings(netdev, &ecmd);
+	if (res < 0)
+		return 0;
+
+	slave_speed = ethtool_cmd_speed(&ecmd);
+	if (slave_speed == 0 || slave_speed == ((__u32) -1))
+		return 0;
+
+	if (DUPLEX_FULL != ecmd.duplex)
+		return 0;
+
+	return 1;
+}
+
 /* if <dev> supports MII link status reporting, check its link status.
  *
  * We either do MII/ETHTOOL ioctls, or check netif_carrier_ok(),
@@ -445,6 +474,11 @@ static int bond_check_dev_link(struct bonding *bond,
 	if (!reporting && !netif_running(slave_dev))
 		return 0;
 
+	/* Check the speed and duplex of the slave device in 802.3ad mode. */
+	if ((BOND_MODE(bond) == BOND_MODE_8023AD) &&
+	   !__check_speed_duplex(slave_dev))
+		return 0;
+
 	if (bond->params.use_carrier)
 		return netif_carrier_ok(slave_dev) ? BMSR_LSTATUS : 0;
 
-- 
1.7.9.5