rt2x00: do not pause queue on flush

Pausing queue on flush make no sense since txdone procedure un-pause
queue. Before flush procedure we have to assure queue is stopped,
i.e. on receive path h/w RX is disabled, on transmit path queue is
disabled in mac80211. That conditions are true except one function:
rt2x00usb_watchdog_tx_dma(), so add stop/start queue there.

Note stop/start queue can be racy if we do this from multiple paths,
but currently we stop TX queues only on rt2x00lib_disable_radio(),
which also stop/sync watchdog, hance we have no race condition.

Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 8 insertions, 31 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index 6c8a33b6ee22..218e3206ce1b 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -1033,38 +1033,21 @@ EXPORT_SYMBOL_GPL(rt2x00queue_stop_queue);
 
 void rt2x00queue_flush_queue(struct data_queue *queue, bool drop)
 {
-        bool started;
         bool tx_queue =
                 (queue->qid == QID_AC_VO) ||
                 (queue->qid == QID_AC_VI) ||
                 (queue->qid == QID_AC_BE) ||
                 (queue->qid == QID_AC_BK);
 
-        mutex_lock(&queue->status_lock);
 
         /*
-         * If the queue has been started, we must stop it temporarily
-         * to prevent any new frames to be queued on the device. If
-         * we are not dropping the pending frames, the queue must
-         * only be stopped in the software and not the hardware,
-         * otherwise the queue will never become empty on its own.
+         * If we are not supposed to drop any pending
+         * frames, this means we must force a start (=kick)
+         * to the queue to make sure the hardware will
+         * start transmitting.
          */
-        started = test_bit(QUEUE_STARTED, &queue->flags);
-        if (started) {
-                /*
-                 * Pause the queue
-                 */
-                rt2x00queue_pause_queue(queue);
-
-                /*
-                 * If we are not supposed to drop any pending
-                 * frames, this means we must force a start (=kick)
-                 * to the queue to make sure the hardware will
-                 * start transmitting.
-                 */
-                if (!drop && tx_queue)
-                        queue->rt2x00dev->ops->lib->kick_queue(queue);
-        }
+        if (!drop && tx_queue)
+                queue->rt2x00dev->ops->lib->kick_queue(queue);
 
         /*
          * Check if driver supports flushing, if that is the case we can
@@ -1080,14 +1063,6 @@ void rt2x00queue_flush_queue(struct data_queue *queue, bool drop)
         if (unlikely(!rt2x00queue_empty(queue)))
                 rt2x00_warn(queue->rt2x00dev, "Queue %d failed to flush\n",
                             queue->qid);
-
-        /*
-         * Restore the queue to the previous status
-         */
-        if (started)
-                rt2x00queue_unpause_queue(queue);
-
-        mutex_unlock(&queue->status_lock);
 }
 EXPORT_SYMBOL_GPL(rt2x00queue_flush_queue);
 
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 88289873c0cf..4e121627925d 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -523,7 +523,9 @@ static void rt2x00usb_watchdog_tx_dma(struct data_queue *queue)
         rt2x00_warn(queue->rt2x00dev, "TX queue %d DMA timed out, invoke forced forced reset\n",
                     queue->qid);
 
+        rt2x00queue_stop_queue(queue);
         rt2x00queue_flush_queue(queue, true);
+        rt2x00queue_start_queue(queue);
 }
 
 static int rt2x00usb_dma_timeout(struct data_queue *queue)