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>

1 files changed, 6 insertions, 15 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 9862c76a83f7..eee66d13e5b9 100644
--- 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);