Revert "IPoIB: Make the carrier_on_task race aware"

This reverts commit 67d7209e1f481cbaed37f9a224a328a3f83d0482.

The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.

Signed-off-by: Roland Dreier <roland@purestorage.com>

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 9862c76..eee66d1 100644 (file)
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -353,27 +353,18 @@ void ipoib_mcast_carrier_on_task(struct work_struct *work)
                                                   carrier_on_task);
        struct ib_port_attr attr;
 
+       /*
+        * Take rtnl_lock to avoid racing with ipoib_stop() and
+        * turning the carrier back on while a device is being
+        * removed.
+        */
        if (ib_query_port(priv->ca, priv->port, &attr) ||
            attr.state != IB_PORT_ACTIVE) {
                ipoib_dbg(priv, "Keeping carrier off until IB port is active\n");
                return;
        }
 
-       /*
-        * Take rtnl_lock to avoid racing with ipoib_stop() and
-        * turning the carrier back on while a device is being
-        * removed.  However, ipoib_stop() will attempt to flush
-        * the workqueue while holding the rtnl lock, so loop
-        * on trylock until either we get the lock or we see
-        * FLAG_ADMIN_UP go away as that signals that we are bailing
-        * and can safely ignore the carrier on work
-        */
-       while (!rtnl_trylock()) {
-               if (!test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
-                       return;
-               else
-                       msleep(20);
-       }
+       rtnl_lock();
        if (!ipoib_cm_admin_enabled(priv->dev))
                dev_set_mtu(priv->dev, min(priv->mcast_mtu, priv->admin_mtu));
        netif_carrier_on(priv->dev);