rt2x00: Make periodic beacon updates for PCI devices atomic

Allow the beacondone and pretbtt functions to update the beacon from
atomic context by using the beacon update functions with caller locking.

This is a preparation for moving the periodic beacon handling into
tasklets that require atomic context.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2x00dev.c

@@ -174,7 +174,13 @@ static void rt2x00lib_beaconupdate_iter(void *data, u8 *mac,
 	    vif->type != NL80211_IFTYPE_WDS)
 		return;
 
-	rt2x00queue_update_beacon(rt2x00dev, vif);
+	/*
+	 * Update the beacon without locking. This is safe on PCI devices
+	 * as they only update the beacon periodically here. This should
+	 * never be called for USB devices.
+	 */
+	WARN_ON(rt2x00_is_usb(rt2x00dev));
+	rt2x00queue_update_beacon_locked(rt2x00dev, vif);
 }
 
 void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
@@ -183,7 +189,7 @@ void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
 		return;
 
 	/* send buffered bc/mc frames out for every bssid */
-	ieee80211_iterate_active_interfaces(rt2x00dev->hw,
+	ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
 						   rt2x00lib_bc_buffer_iter,
 						   rt2x00dev);
 	/*
@@ -195,7 +201,7 @@ void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
 		return;
 
 	/* fetch next beacon */
-	ieee80211_iterate_active_interfaces(rt2x00dev->hw,
+	ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
 						   rt2x00lib_beaconupdate_iter,
 						   rt2x00dev);
 }
@@ -207,7 +213,7 @@ void rt2x00lib_pretbtt(struct rt2x00_dev *rt2x00dev)
 		return;
 
 	/* fetch next beacon */
-	ieee80211_iterate_active_interfaces(rt2x00dev->hw,
+	ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
 						   rt2x00lib_beaconupdate_iter,
 						   rt2x00dev);
 }