cfg80211: provide channel to join_mesh function

Just like the AP mode patch, instead of setting
the channel and then joining the mesh network,
provide the channel to join the network on to
the join_mesh() function.

Like in AP mode, you can also give the channel
to the join-mesh nl80211 command now.

Unlike AP mode, it picks a default channel if
none was given.

As libertas uses mesh mode interfaces but has
no join_mesh callback and we can't simply break
it, keep some compatibility code for that case
and configure the channel directly for it.

In the non-libertas case, where we store the
channel until join, allow setting it while the
interface is down.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index b082fcc..faeb035 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -796,7 +796,6 @@
 	case NL80211_IFTYPE_ADHOC:
 		return cfg80211_ibss_wext_siwfreq(dev, info, wextfreq, extra);
 	case NL80211_IFTYPE_MONITOR:
-	case NL80211_IFTYPE_MESH_POINT:
 		freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
 		if (freq < 0)
 			return freq;
@@ -808,6 +807,17 @@
 		wdev_unlock(wdev);
 		mutex_unlock(&rdev->devlist_mtx);
 		return err;
+	case NL80211_IFTYPE_MESH_POINT:
+		freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
+		if (freq < 0)
+			return freq;
+		if (freq == 0)
+			return -EINVAL;
+		mutex_lock(&rdev->devlist_mtx);
+		err = cfg80211_set_mesh_freq(rdev, wdev, freq,
+					     NL80211_CHAN_NO_HT);
+		mutex_unlock(&rdev->devlist_mtx);
+		return err;
 	default:
 		return -EOPNOTSUPP;
 	}