mac80211: explicitly disable/enable QoS

Add interface to disable/enable QoS (aka WMM or WME). Currently drivers
enable it explicitly when ->conf_tx method is called, and newer disable.
Disabling is needed for some APs, which do not support QoS, such
we should send QoS frames to them.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 65eafda..c686d1b 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -586,6 +586,9 @@
 	int count;
 	u8 *pos, uapsd_queues = 0;
 
+	if (!local->ops->conf_tx)
+		return;
+
 	if (local->hw.queues < 4)
 		return;
 
@@ -660,11 +663,15 @@
 		       params.aifs, params.cw_min, params.cw_max, params.txop,
 		       params.uapsd);
 #endif
-		if (drv_conf_tx(local, queue, &params) && local->ops->conf_tx)
+		if (drv_conf_tx(local, queue, &params))
 			printk(KERN_DEBUG "%s: failed to set TX queue "
 			       "parameters for queue %d\n",
 			       wiphy_name(local->hw.wiphy), queue);
 	}
+
+	/* enable WMM or activate new settings */
+	local->hw.conf.flags |=	IEEE80211_CONF_QOS;
+	drv_config(local, IEEE80211_CONF_CHANGE_QOS);
 }
 
 static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,