rt2x00: Protect queue control with mutex

Add wrapper functions in rt2x00queue.c to
start & stop queues. This control must be protected
using a mutex.

Queues can also be paused which will halt the flow
of packets between the driver and mac80211. This doesn't
require a mutex protection.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2x00.h

@@ -1073,6 +1073,58 @@ struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
 struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
 					  enum queue_index index);
 
+/**
+ * rt2x00queue_pause_queue - Pause a data queue
+ * @queue: Pointer to &struct data_queue.
+ *
+ * This function will pause the data queue locally, preventing
+ * new frames to be added to the queue (while the hardware is
+ * still allowed to run).
+ */
+void rt2x00queue_pause_queue(struct data_queue *queue);
+
+/**
+ * rt2x00queue_unpause_queue - unpause a data queue
+ * @queue: Pointer to &struct data_queue.
+ *
+ * This function will unpause the data queue locally, allowing
+ * new frames to be added to the queue again.
+ */
+void rt2x00queue_unpause_queue(struct data_queue *queue);
+
+/**
+ * rt2x00queue_start_queue - Start a data queue
+ * @queue: Pointer to &struct data_queue.
+ *
+ * This function will start handling all pending frames in the queue.
+ */
+void rt2x00queue_start_queue(struct data_queue *queue);
+
+/**
+ * rt2x00queue_stop_queue - Halt a data queue
+ * @queue: Pointer to &struct data_queue.
+ *
+ * This function will stop all pending frames in the queue.
+ */
+void rt2x00queue_stop_queue(struct data_queue *queue);
+
+/**
+ * rt2x00queue_start_queues - Start all data queues
+ * @rt2x00dev: Pointer to &struct rt2x00_dev.
+ *
+ * This function will loop through all available queues to start them
+ */
+void rt2x00queue_start_queues(struct rt2x00_dev *rt2x00dev);
+
+/**
+ * rt2x00queue_stop_queues - Halt all data queues
+ * @rt2x00dev: Pointer to &struct rt2x00_dev.
+ *
+ * This function will loop through all available queues to stop
+ * any pending frames.
+ */
+void rt2x00queue_stop_queues(struct rt2x00_dev *rt2x00dev);
+
 /*
  * Debugfs handlers.
  */

drivers/net/wireless/rt2x00/rt2x00config.c

@@ -146,7 +146,7 @@ void rt2x00lib_config_antenna(struct rt2x00_dev *rt2x00dev,
 	 * else the changes will be ignored by the device.
 	 */
 	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
-		rt2x00dev->ops->lib->stop_queue(rt2x00dev->rx);
+		rt2x00queue_stop_queue(rt2x00dev->rx);
 
 	/*
 	 * Write new antenna setup to device and reset the link tuner.
@@ -160,7 +160,7 @@ void rt2x00lib_config_antenna(struct rt2x00_dev *rt2x00dev,
 	memcpy(active, &config, sizeof(config));
 
 	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
-		rt2x00dev->ops->lib->start_queue(rt2x00dev->rx);
+		rt2x00queue_start_queue(rt2x00dev->rx);
 }
 
 void rt2x00lib_config(struct rt2x00_dev *rt2x00dev,

drivers/net/wireless/rt2x00/rt2x00debug.c

@@ -339,12 +339,13 @@ static ssize_t rt2x00debug_read_queue_stats(struct file *file,
 		return -ENOMEM;
 
 	temp = data +
-	    sprintf(data, "qid\tcount\tlimit\tlength\tindex\tdma done\tdone\n");
+	    sprintf(data, "qid\tflags\t\tcount\tlimit\tlength\tindex\tdma done\tdone\n");
 
 	queue_for_each(intf->rt2x00dev, queue) {
 		spin_lock_irqsave(&queue->index_lock, irqflags);
 
-		temp += sprintf(temp, "%d\t%d\t%d\t%d\t%d\t%d\t%d\n", queue->qid,
+		temp += sprintf(temp, "%d\t0x%.8x\t%d\t%d\t%d\t%d\t%d\t\t%d\n",
+				queue->qid, (unsigned int)queue->flags,
 				queue->count, queue->limit, queue->length,
 				queue->index[Q_INDEX],
 				queue->index[Q_INDEX_DMA_DONE],

drivers/net/wireless/rt2x00/rt2x00dev.c

@@ -66,21 +66,16 @@ int rt2x00lib_enable_radio(struct rt2x00_dev *rt2x00dev)
 	set_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags);
 
 	/*
-	 * Enable RX.
+	 * Enable queues.
 	 */
-	rt2x00dev->ops->lib->start_queue(rt2x00dev->rx);
+	rt2x00queue_start_queues(rt2x00dev);
 	rt2x00link_start_tuner(rt2x00dev);
 
 	/*
 	 * Start watchdog monitoring.
 	 */
 	rt2x00link_start_watchdog(rt2x00dev);
 
-	/*
-	 * Start the TX queues.
-	 */
-	ieee80211_wake_queues(rt2x00dev->hw);
-
 	return 0;
 }
 
@@ -89,22 +84,16 @@ void rt2x00lib_disable_radio(struct rt2x00_dev *rt2x00dev)
 	if (!test_and_clear_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return;
 
-	/*
-	 * Stop the TX queues in mac80211.
-	 */
-	ieee80211_stop_queues(rt2x00dev->hw);
-	rt2x00queue_stop_queues(rt2x00dev);
-
 	/*
 	 * Stop watchdog monitoring.
 	 */
 	rt2x00link_stop_watchdog(rt2x00dev);
 
 	/*
-	 * Disable RX.
+	 * Stop all queues
 	 */
 	rt2x00link_stop_tuner(rt2x00dev);
-	rt2x00dev->ops->lib->stop_queue(rt2x00dev->rx);
+	rt2x00queue_stop_queues(rt2x00dev);
 
 	/*
 	 * Disable radio.
@@ -249,7 +238,6 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
-	enum data_queue_qid qid = skb_get_queue_mapping(entry->skb);
 	unsigned int header_length, i;
 	u8 rate_idx, rate_flags, retry_rates;
 	u8 skbdesc_flags = skbdesc->flags;
@@ -403,7 +391,7 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 	 * is reenabled when the txdone handler has finished.
 	 */
 	if (!rt2x00queue_threshold(entry->queue))
-		ieee80211_wake_queue(rt2x00dev->hw, qid);
+		rt2x00queue_unpause_queue(entry->queue);
 }
 EXPORT_SYMBOL_GPL(rt2x00lib_txdone);
 

drivers/net/wireless/rt2x00/rt2x00lib.h

@@ -177,15 +177,6 @@ int rt2x00queue_update_beacon(struct rt2x00_dev *rt2x00dev,
  */
 void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index);
 
-/**
- * rt2x00queue_stop_queues - Halt all data queues
- * @rt2x00dev: Pointer to &struct rt2x00_dev.
- *
- * This function will loop through all available queues to stop
- * any pending outgoing frames.
- */
-void rt2x00queue_stop_queues(struct rt2x00_dev *rt2x00dev);
-
 /**
  * rt2x00queue_init_queues - Initialize all data queues
  * @rt2x00dev: Pointer to &struct rt2x00_dev.

drivers/net/wireless/rt2x00/rt2x00mac.c

@@ -104,7 +104,7 @@ int rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
 	enum data_queue_qid qid = skb_get_queue_mapping(skb);
-	struct data_queue *queue;
+	struct data_queue *queue = NULL;
 
 	/*
 	 * Mac80211 might be calling this function while we are trying
@@ -153,7 +153,7 @@ int rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 		goto exit_fail;
 
 	if (rt2x00queue_threshold(queue))
-		ieee80211_stop_queue(rt2x00dev->hw, qid);
+		rt2x00queue_pause_queue(queue);
 
 	return NETDEV_TX_OK;
 
@@ -352,7 +352,7 @@ int rt2x00mac_config(struct ieee80211_hw *hw, u32 changed)
 	 * if for any reason the link tuner must be reset, this will be
 	 * handled by rt2x00lib_config().
 	 */
-	rt2x00dev->ops->lib->stop_queue(rt2x00dev->rx);
+	rt2x00queue_stop_queue(rt2x00dev->rx);
 
 	/*
 	 * When we've just turned on the radio, we want to reprogram
@@ -370,7 +370,7 @@ int rt2x00mac_config(struct ieee80211_hw *hw, u32 changed)
 	rt2x00lib_config_antenna(rt2x00dev, rt2x00dev->default_ant);
 
 	/* Turn RX back on */
-	rt2x00dev->ops->lib->start_queue(rt2x00dev->rx);
+	rt2x00queue_start_queue(rt2x00dev->rx);
 
 	return 0;
 }

drivers/net/wireless/rt2x00/rt2x00queue.c

@@ -585,7 +585,7 @@ int rt2x00queue_update_beacon(struct rt2x00_dev *rt2x00dev,
 	rt2x00queue_free_skb(intf->beacon);
 
 	if (!enable_beacon) {
-		rt2x00dev->ops->lib->stop_queue(intf->beacon->queue);
+		rt2x00queue_stop_queue(intf->beacon->queue);
 		mutex_unlock(&intf->beacon_skb_mutex);
 		return 0;
 	}
@@ -738,6 +738,125 @@ void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
 	spin_unlock_irqrestore(&queue->index_lock, irqflags);
 }
 
+void rt2x00queue_pause_queue(struct data_queue *queue)
+{
+	if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
+	    !test_bit(QUEUE_STARTED, &queue->flags) ||
+	    test_and_set_bit(QUEUE_PAUSED, &queue->flags))
+		return;
+
+	switch (queue->qid) {
+	case QID_AC_BE:
+	case QID_AC_BK:
+	case QID_AC_VI:
+	case QID_AC_VO:
+		/*
+		 * For TX queues, we have to disable the queue
+		 * inside mac80211.
+		 */
+		ieee80211_stop_queue(queue->rt2x00dev->hw, queue->qid);
+		break;
+	default:
+		break;
+	}
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_pause_queue);
+
+void rt2x00queue_unpause_queue(struct data_queue *queue)
+{
+	if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
+	    !test_bit(QUEUE_STARTED, &queue->flags) ||
+	    !test_and_clear_bit(QUEUE_PAUSED, &queue->flags))
+		return;
+
+	switch (queue->qid) {
+	case QID_AC_BE:
+	case QID_AC_BK:
+	case QID_AC_VI:
+	case QID_AC_VO:
+		/*
+		 * For TX queues, we have to enable the queue
+		 * inside mac80211.
+		 */
+		ieee80211_wake_queue(queue->rt2x00dev->hw, queue->qid);
+		break;
+	default:
+		break;
+	}
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_unpause_queue);
+
+void rt2x00queue_start_queue(struct data_queue *queue)
+{
+	mutex_lock(&queue->status_lock);
+
+	if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
+	    test_and_set_bit(QUEUE_STARTED, &queue->flags)) {
+		mutex_unlock(&queue->status_lock);
+		return;
+	}
+
+	set_bit(QUEUE_PAUSED, &queue->flags);
+
+	queue->rt2x00dev->ops->lib->start_queue(queue);
+
+	rt2x00queue_unpause_queue(queue);
+
+	mutex_unlock(&queue->status_lock);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_start_queue);
+
+void rt2x00queue_stop_queue(struct data_queue *queue)
+{
+	mutex_lock(&queue->status_lock);
+
+	if (!test_and_clear_bit(QUEUE_STARTED, &queue->flags)) {
+		mutex_unlock(&queue->status_lock);
+		return;
+	}
+
+	rt2x00queue_pause_queue(queue);
+
+	queue->rt2x00dev->ops->lib->stop_queue(queue);
+
+	mutex_unlock(&queue->status_lock);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_stop_queue);
+
+void rt2x00queue_start_queues(struct rt2x00_dev *rt2x00dev)
+{
+	struct data_queue *queue;
+
+	/*
+	 * rt2x00queue_start_queue will call ieee80211_wake_queue
+	 * for each queue after is has been properly initialized.
+	 */
+	tx_queue_for_each(rt2x00dev, queue)
+		rt2x00queue_start_queue(queue);
+
+	rt2x00queue_start_queue(rt2x00dev->rx);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_start_queues);
+
+void rt2x00queue_stop_queues(struct rt2x00_dev *rt2x00dev)
+{
+	struct data_queue *queue;
+
+	/*
+	 * rt2x00queue_stop_queue will call ieee80211_stop_queue
+	 * as well, but we are completely shutting doing everything
+	 * now, so it is much safer to stop all TX queues at once,
+	 * and use rt2x00queue_stop_queue for cleaning up.
+	 */
+	ieee80211_stop_queues(rt2x00dev->hw);
+
+	tx_queue_for_each(rt2x00dev, queue)
+		rt2x00queue_stop_queue(queue);
+
+	rt2x00queue_stop_queue(rt2x00dev->rx);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_stop_queues);
+
 static void rt2x00queue_reset(struct data_queue *queue)
 {
 	unsigned long irqflags;
@@ -756,14 +875,6 @@ static void rt2x00queue_reset(struct data_queue *queue)
 	spin_unlock_irqrestore(&queue->index_lock, irqflags);
 }
 
-void rt2x00queue_stop_queues(struct rt2x00_dev *rt2x00dev)
-{
-	struct data_queue *queue;
-
-	txall_queue_for_each(rt2x00dev, queue)
-		rt2x00dev->ops->lib->stop_queue(queue);
-}
-
 void rt2x00queue_init_queues(struct rt2x00_dev *rt2x00dev)
 {
 	struct data_queue *queue;
@@ -905,6 +1016,7 @@ void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
 static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
 			     struct data_queue *queue, enum data_queue_qid qid)
 {
+	mutex_init(&queue->status_lock);
 	spin_lock_init(&queue->index_lock);
 
 	queue->rt2x00dev = rt2x00dev;