rt2x00: Move TX/RX work into dedicated workqueue

The TX/RX work structures must be able to run independently
of other workqueues. This is because mac80211 might use
the flush() callback function from various context, which depends
on the TX/RX work to complete while the main thread is blocked
(until the the TX queues are empty).

This should reduce the number of  'Queue %d failed to flush' warnings.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index e716285..9de9dbe 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -997,8 +997,15 @@
 		    BIT(NL80211_IFTYPE_WDS);
 
 	/*
-	 * Initialize configuration work.
+	 * Initialize work.
 	 */
+	rt2x00dev->workqueue =
+	    alloc_ordered_workqueue(wiphy_name(rt2x00dev->hw->wiphy), 0);
+	if (!rt2x00dev->workqueue) {
+		retval = -ENOMEM;
+		goto exit;
+	}
+
 	INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
 
 	/*
@@ -1057,6 +1064,7 @@
 	cancel_work_sync(&rt2x00dev->intf_work);
 	cancel_work_sync(&rt2x00dev->rxdone_work);
 	cancel_work_sync(&rt2x00dev->txdone_work);
+	destroy_workqueue(rt2x00dev->workqueue);
 
 	/*
 	 * Free the tx status fifo.