All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH 1/6] rt2x00: Serialize TX operations on a queue.
@ 2011-07-06 20:56 Ivo van Doorn
  2011-07-06 20:57 ` [PATCH 2/6] rt2x00: Don't use queue entry as parameter when creating TX descriptor Ivo van Doorn
  0 siblings, 1 reply; 6+ messages in thread
From: Ivo van Doorn @ 2011-07-06 20:56 UTC (permalink / raw)
  To: John W. Linville; +Cc: users, linux-wireless

From: Gertjan van Wingerde <gwingerde@gmail.com>

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: Andreas Hartmann <andihartmann@01019freenet.de>
Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
 drivers/net/wireless/rt2x00/rt2x00queue.c |   21 ++++++++++++++++-----
 drivers/net/wireless/rt2x00/rt2x00queue.h |    2 ++
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index c7fc9de..551cee1 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -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;
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.h b/drivers/net/wireless/rt2x00/rt2x00queue.h
index 5900474..f2100f4 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.h
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.h
@@ -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;
-- 
1.7.2.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-07-06 21:01 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-07-06 20:56 [PATCH 1/6] rt2x00: Serialize TX operations on a queue Ivo van Doorn
2011-07-06 20:57 ` [PATCH 2/6] rt2x00: Don't use queue entry as parameter when creating TX descriptor Ivo van Doorn
2011-07-06 20:57   ` [PATCH 3/6] rt2x00: Reduce window of a queue's tx lock Ivo van Doorn
2011-07-06 20:58     ` [PATCH 4/6] rt2x00: Add device ID for RT539F device Ivo van Doorn
2011-07-06 20:59       ` [PATCH 5/6] rt2x00: Properly identify rt2800usb devices Ivo van Doorn
2011-07-06 21:00         ` [PATCH 6/6] rt2x00: Implement tx_frames_pending mac80211 callback function Ivo van Doorn

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.