mac80211: manage carrier state in mesh

Instead of assuming the carrier is on all
the time in mesh manage it with joining
and leaving the mesh.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 03f1696..571d518 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -610,6 +610,8 @@
 						BSS_CHANGED_HT |
 						BSS_CHANGED_BASIC_RATES |
 						BSS_CHANGED_BEACON_INT);
+
+	netif_carrier_on(sdata->dev);
 }
 
 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
@@ -617,6 +619,8 @@
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 
+	netif_carrier_off(sdata->dev);
+
 	ifmsh->mesh_id_len = 0;
 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
 	sta_info_flush(local, NULL);