bonding:update speed/duplex for NETDEV_CHANGE

Zheng Liang(lzheng@redhat.com) found a bug that if we config bonding with
arp monitor, sometimes bonding driver cannot get the speed and duplex from
its slaves, it will assume them to be 100Mb/sec and Full, please see
/proc/net/bonding/bond0.
But there is no such problem when uses miimon.

(Take igb for example)
I find that the reason is that after dev_open() in bond_enslave(),
bond_update_speed_duplex() will call igb_get_settings()
, but in that function,
it runs ethtool_cmd_speed_set(ecmd, -1); ecmd->duplex = -1;
because igb get an error value of status.
So even dev_open() is called, but the device is not really ready to get its
settings.

Maybe it is safe for us to call igb_get_settings() only after
this message shows up, that is "igb: p4p1 NIC Link is Up 1000 Mbps Full Duplex,
Flow Control: RX".

So I prefer to update the speed and duplex for a slave when reseices
NETDEV_CHANGE/NETDEV_UP event.

Changelog
V2:
1 remove the "fake 100/Full" logic in bond_update_speed_duplex(),
  set speed and duplex to -1 when it gets error value of speed and duplex.
2 delete the warning in bond_enslave() if bond_update_speed_duplex() returns
  error.
3 make bond_info_show_slave() handle bad values of speed and duplex.

Signed-off-by: Weiping Pan <wpan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 25 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index c34cc1e7c6f6..b2b9109b6712 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -550,7 +550,7 @@ down:
 /*
  * Get link speed and duplex from the slave's base driver
  * using ethtool. If for some reason the call fails or the
- * values are invalid, fake speed and duplex to 100/Full
+ * values are invalid, set speed and duplex to -1,
  * and return error.
  */
 static int bond_update_speed_duplex(struct slave *slave)
@@ -560,9 +560,8 @@ static int bond_update_speed_duplex(struct slave *slave)
         u32 slave_speed;
         int res;
 
-        /* Fake speed and duplex */
-        slave->speed = SPEED_100;
-        slave->duplex = DUPLEX_FULL;
+        slave->speed = -1;
+        slave->duplex = -1;
 
         res = __ethtool_get_settings(slave_dev, &ecmd);
         if (res < 0)
@@ -1751,16 +1750,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
                 new_slave->link  = BOND_LINK_DOWN;
         }
 
-        if (bond_update_speed_duplex(new_slave) &&
-            (new_slave->link != BOND_LINK_DOWN)) {
-                pr_warning("%s: Warning: failed to get speed and duplex from %s, assumed to be 100Mb/sec and Full.\n",
-                           bond_dev->name, new_slave->dev->name);
-
-                if (bond->params.mode == BOND_MODE_8023AD) {
-                        pr_warning("%s: Warning: Operation of 802.3ad mode requires ETHTOOL support in base driver for proper aggregator selection.\n",
-                                   bond_dev->name);
-                }
-        }
+        bond_update_speed_duplex(new_slave);
 
         if (USES_PRIMARY(bond->params.mode) && bond->params.primary[0]) {
                 /* if there is a primary slave, remember it */
@@ -3220,6 +3210,7 @@ static int bond_slave_netdev_event(unsigned long event,
 {
         struct net_device *bond_dev = slave_dev->master;
         struct bonding *bond = netdev_priv(bond_dev);
+        struct slave *slave = NULL;
 
         switch (event) {
         case NETDEV_UNREGISTER:
@@ -3230,20 +3221,16 @@ static int bond_slave_netdev_event(unsigned long event,
                                 bond_release(bond_dev, slave_dev);
                 }
                 break;
+        case NETDEV_UP:
         case NETDEV_CHANGE:
-                if (bond->params.mode == BOND_MODE_8023AD || bond_is_lb(bond)) {
-                        struct slave *slave;
+                slave = bond_get_slave_by_dev(bond, slave_dev);
+                if (slave) {
+                        u32 old_speed = slave->speed;
+                        u8  old_duplex = slave->duplex;
 
-                        slave = bond_get_slave_by_dev(bond, slave_dev);
-                        if (slave) {
-                                u32 old_speed = slave->speed;
-                                u8  old_duplex = slave->duplex;
-
-                                bond_update_speed_duplex(slave);
-
-                                if (bond_is_lb(bond))
-                                        break;
+                        bond_update_speed_duplex(slave);
 
+                        if (bond->params.mode == BOND_MODE_8023AD) {
                                 if (old_speed != slave->speed)
                                         bond_3ad_adapter_speed_changed(slave);
                                 if (old_duplex != slave->duplex)