rt2x00: Don't kick TX queue after each frame
TX queues shouldn't be kicked after each frame that is put into the
queue. This could cause problems during RTS and CTS-to-self as well
as with fragmentation. In all those cases you want all frames to be
send out in a single burst. Off course we shouldn't let the queue fill
up entirely, thus we introduce a 10% threshold which, when reached,
will force the frames to be send out regardless of the frame.
In addition we should prevent queues to become full in such a way
that the tx() handler can fail. Instead of stopping the queue when
it is full, we should stop it when it is below the threshold.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index f875b7a..4930665 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -163,8 +163,8 @@
void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
struct txentry_desc *txdesc)
{
- struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
- struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
+ struct data_queue *queue = entry->queue;
+ struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
rt2x00dev->ops->lib->write_tx_desc(rt2x00dev, entry->skb, txdesc);
@@ -175,16 +175,21 @@
rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TX, entry->skb);
/*
- * We are done writing the frame to the queue entry,
- * also kick the queue in case the correct flags are set,
- * note that this will automatically filter beacons and
- * RTS/CTS frames since those frames don't have this flag
- * set.
+ * Check if we need to kick the queue, there are however a few rules
+ * 1) Don't kick beacon queue
+ * 2) Don't kick unless this is the last in frame in a burst.
+ * When the burst flag is set, this frame is always followed
+ * by another frame which in some way are related to eachother.
+ * This is true for fragments, RTS or CTS-to-self frames.
+ * 3) Rule 2 can be broken when the available entries
+ * in the queue are less then a certain threshold.
*/
- if (rt2x00dev->ops->lib->kick_tx_queue &&
- !(skbdesc->flags & FRAME_DESC_DRIVER_GENERATED))
- rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev,
- entry->queue->qid);
+ if (entry->queue->qid == QID_BEACON)
+ return;
+
+ if (rt2x00queue_threshold(queue) ||
+ !test_bit(ENTRY_TXD_BURST, &txdesc->flags))
+ rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev, queue->qid);
}
EXPORT_SYMBOL_GPL(rt2x00queue_write_tx_descriptor);
@@ -349,6 +354,7 @@
rt2x00queue_reset(queue);
queue->limit = qdesc->entry_num;
+ queue->threshold = DIV_ROUND_UP(qdesc->entry_num, 10);
queue->data_size = qdesc->data_size;
queue->desc_size = qdesc->desc_size;