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Commit 77a861c4 authored by Gertjan van Wingerde's avatar Gertjan van Wingerde Committed by John W. Linville
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rt2x00: Serialize TX operations on a queue. 



The rt2x00 driver gets frequent occurrences of the following error message
when operating under load:
phy0 -> rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the
non-full queue 2.

This is caused by simultaneous attempts from mac80211 to send a frame via
rt2x00, which are not properly serialized inside rt2x00queue_write_tx_frame,
causing the second frame to fail sending with the above mentioned error
message.

Fix this by introducing a per-queue spinlock to serialize the TX operations
on that queue.

Reported-by: default avatarAndreas Hartmann <andihartmann@01019freenet.de>
Signed-off-by: default avatarGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: default avatarHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: default avatarIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 9352f69c

drivers/net/wireless/rt2x00/rt2x00queue.c

+16 −5
Original line number Diff line number Diff line
@@ -555,15 +555,21 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb, 
			       bool local)

{

	struct ieee80211_tx_info *tx_info;

	struct queue_entry *entry = rt2x00queue_get_entry(queue, Q_INDEX);

	struct queue_entry *entry;

	struct txentry_desc txdesc;

	struct skb_frame_desc *skbdesc;

	u8 rate_idx, rate_flags;

	int ret = 0;



	spin_lock(&queue->tx_lock);



	entry = rt2x00queue_get_entry(queue, Q_INDEX);



	if (unlikely(rt2x00queue_full(queue))) {

		ERROR(queue->rt2x00dev,

		      "Dropping frame due to full tx queue %d.\n", queue->qid);

		return -ENOBUFS;

		ret = -ENOBUFS;

		goto out;

	}



	if (unlikely(test_and_set_bit(ENTRY_OWNER_DEVICE_DATA,
@@ -572,7 +578,8 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb, 
		      "Arrived at non-free entry in the non-full queue %d.\n"

		      "Please file bug report to %s.\n",

		      queue->qid, DRV_PROJECT);

		return -EINVAL;

		ret = -EINVAL;

		goto out;

	}



	/*
@@ -634,7 +641,8 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb, 
	if (unlikely(rt2x00queue_write_tx_data(entry, &txdesc))) {

		clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);

		entry->skb = NULL;

		return -EIO;

		ret = -EIO;

		goto out;

	}



	set_bit(ENTRY_DATA_PENDING, &entry->flags);
@@ -643,7 +651,9 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb, 
	rt2x00queue_write_tx_descriptor(entry, &txdesc);

	rt2x00queue_kick_tx_queue(queue, &txdesc);



	return 0;

out:

	spin_unlock(&queue->tx_lock);

	return ret;

}



int rt2x00queue_clear_beacon(struct rt2x00_dev *rt2x00dev,
@@ -1184,6 +1194,7 @@ 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->tx_lock);

	spin_lock_init(&queue->index_lock);



	queue->rt2x00dev = rt2x00dev;

drivers/net/wireless/rt2x00/rt2x00queue.h

+2 −0
Original line number Diff line number Diff line
@@ -432,6 +432,7 @@ enum data_queue_flags { 
 * @flags: Entry flags, see &enum queue_entry_flags.

 * @status_lock: The mutex for protecting the start/stop/flush

 *	handling on this queue.

 * @tx_lock: Spinlock to serialize tx operations on this queue.

 * @index_lock: Spinlock to protect index handling. Whenever @index, @index_done or

 *	@index_crypt needs to be changed this lock should be grabbed to prevent

 *	index corruption due to concurrency.
@@ -458,6 +459,7 @@ struct data_queue { 
	unsigned long flags;



	struct mutex status_lock;

	spinlock_t tx_lock;

	spinlock_t index_lock;



	unsigned int count;