[BRIDGE]: handle speed detection after carrier changes

Speed of a interface may not be available until carrier
is detected in the case of autonegotiation. To get the correct value
we need to recheck speed after carrier event.  But the check needs to
be done in a context that is similar to normal ethtool interface (can sleep).

Also, delay check for 1ms to try avoid any carrier bounce transitions.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 975abe254b7a9b37462974fdc7448f9cd22cac8d..e6b8bb51d613d790fa3940b7e172bd7a23771b60 100644 (file)
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -32,9 +32,8 @@
  * ethtool, use ethtool_ops.  Also, since driver might sleep need to
  * not be holding any locks.
  */
-static int br_initial_port_cost(struct net_device *dev)
+static int port_cost(struct net_device *dev)
 {
-
        struct ethtool_cmd ecmd = { ETHTOOL_GSET };
        struct ifreq ifr;
        mm_segment_t old_fs;
@@ -58,10 +57,6 @@ static int br_initial_port_cost(struct net_device *dev)
                        return 2;
                case SPEED_10:
                        return 100;
-               default:
-                       pr_info("bridge: can't decode speed from %s: %d\n",
-                               dev->name, ecmd.speed);
-                       return 100;
                }
        }
 
@@ -75,6 +70,35 @@ static int br_initial_port_cost(struct net_device *dev)
        return 100;     /* assume old 10Mbps */
 }
 
+
+/*
+ * Check for port carrier transistions.
+ * Called from work queue to allow for calling functions that
+ * might sleep (such as speed check), and to debounce.
+ */
+static void port_carrier_check(void *arg)
+{
+       struct net_bridge_port *p = arg;
+
+       rtnl_lock();
+       if (netif_carrier_ok(p->dev)) {
+               u32 cost = port_cost(p->dev);
+
+               spin_lock_bh(&p->br->lock);
+               if (p->state == BR_STATE_DISABLED) {
+                       p->path_cost = cost;
+                       br_stp_enable_port(p);
+               }
+               spin_unlock_bh(&p->br->lock);
+       } else {
+               spin_lock_bh(&p->br->lock);
+               if (p->state != BR_STATE_DISABLED)
+                       br_stp_disable_port(p);
+               spin_unlock_bh(&p->br->lock);
+       }
+       rtnl_unlock();
+}
+
 static void destroy_nbp(struct net_bridge_port *p)
 {
        struct net_device *dev = p->dev;
@@ -102,6 +126,9 @@ static void del_nbp(struct net_bridge_port *p)
        dev->br_port = NULL;
        dev_set_promiscuity(dev, -1);
 
+       cancel_delayed_work(&p->carrier_check);
+       flush_scheduled_work();
+
        spin_lock_bh(&br->lock);
        br_stp_disable_port(p);
        spin_unlock_bh(&br->lock);
@@ -195,10 +222,9 @@ static int find_portno(struct net_bridge *br)
        return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 }
 
-/* called with RTNL */
+/* called with RTNL but without bridge lock */
 static struct net_bridge_port *new_nbp(struct net_bridge *br, 
-                                      struct net_device *dev,
-                                      unsigned long cost)
+                                      struct net_device *dev)
 {
        int index;
        struct net_bridge_port *p;
@@ -215,12 +241,13 @@ static struct net_bridge_port *new_nbp(struct net_bridge *br,
        p->br = br;
        dev_hold(dev);
        p->dev = dev;
-       p->path_cost = cost;
+       p->path_cost = port_cost(dev);
        p->priority = 0x8000 >> BR_PORT_BITS;
        dev->br_port = p;
        p->port_no = index;
        br_init_port(p);
        p->state = BR_STATE_DISABLED;
+       INIT_WORK(&p->carrier_check, port_carrier_check, p);
        kobject_init(&p->kobj);
 
        return p;
@@ -351,7 +378,7 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
        if (dev->br_port != NULL)
                return -EBUSY;
 
-       if (IS_ERR(p = new_nbp(br, dev, br_initial_port_cost(dev))))
+       if (IS_ERR(p = new_nbp(br, dev)))
                return PTR_ERR(p);
 
        if ((err = br_fdb_insert(br, p, dev->dev_addr)))

diff --git a/net/bridge/br_notify.c b/net/bridge/br_notify.c
index 917311c6828b9c5c70d2290c617c4ebaf9be3405..a43a9c1d50d7daa21c732523e9d2cdb3d36e3a9e 100644 (file)
--- a/net/bridge/br_notify.c
+++ b/net/bridge/br_notify.c
@@ -52,17 +52,9 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
                br_stp_recalculate_bridge_id(br);
                break;
 
-       case NETDEV_CHANGE:     /* device is up but carrier changed */
-               if (!(br->dev->flags & IFF_UP))
-                       break;
-
-               if (netif_carrier_ok(dev)) {
-                       if (p->state == BR_STATE_DISABLED)
-                               br_stp_enable_port(p);
-               } else {
-                       if (p->state != BR_STATE_DISABLED)
-                               br_stp_disable_port(p);
-               }
+       case NETDEV_CHANGE:
+               if (br->dev->flags & IFF_UP)
+                       schedule_delayed_work(&p->carrier_check, BR_PORT_DEBOUNCE);
                break;
 
        case NETDEV_FEAT_CHANGE:

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 2c249486476f8a4253277457b8cf27be201d6875..7ad53c2aa6845efc6576b2347e4acbc7229bff82 100644 (file)
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -27,6 +27,8 @@
 #define BR_PORT_BITS   10
 #define BR_MAX_PORTS   (1<<BR_PORT_BITS)
 
+#define BR_PORT_DEBOUNCE (HZ/10)
+
 typedef struct bridge_id bridge_id;
 typedef struct mac_addr mac_addr;
 typedef __u16 port_id;
@@ -78,6 +80,7 @@ struct net_bridge_port
        struct timer_list               hold_timer;
        struct timer_list               message_age_timer;
        struct kobject                  kobj;
+       struct work_struct              carrier_check;
        struct rcu_head                 rcu;
 };