rt2x00: Reduce window of a queue's tx lock.

Currently a lot of actions that can be done without the queue's tx lock
being held are done inside the locked area.
Move them out to have a leaner and meaner code that operates while the
tx lock is being held.

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>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 26 insertions, 25 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index a70e7000b528..29edb9fbe6f1 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -565,33 +565,11 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
         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);
-                ret = -ENOBUFS;
-                goto out;
-        }
-
-        if (unlikely(test_and_set_bit(ENTRY_OWNER_DEVICE_DATA,
-                                      &entry->flags))) {
-                ERROR(queue->rt2x00dev,
-                      "Arrived at non-free entry in the non-full queue %d.\n"
-                      "Please file bug report to %s.\n",
-                      queue->qid, DRV_PROJECT);
-                ret = -EINVAL;
-                goto out;
-        }
-
         /*
          * Copy all TX descriptor information into txdesc,
          * after that we are free to use the skb->cb array
          * for our information.
          */
-        entry->skb = skb;
         rt2x00queue_create_tx_descriptor(queue->rt2x00dev, skb, &txdesc);
 
         /*
@@ -604,7 +582,6 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
         rate_flags = tx_info->control.rates[0].flags;
         skbdesc = get_skb_frame_desc(skb);
         memset(skbdesc, 0, sizeof(*skbdesc));
-        skbdesc->entry = entry;
         skbdesc->tx_rate_idx = rate_idx;
         skbdesc->tx_rate_flags = rate_flags;
 
@@ -633,9 +610,33 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
          * for PCI devices.
          */
         if (test_bit(REQUIRE_L2PAD, &queue->rt2x00dev->cap_flags))
-                rt2x00queue_insert_l2pad(entry->skb, txdesc.header_length);
+                rt2x00queue_insert_l2pad(skb, txdesc.header_length);
         else if (test_bit(REQUIRE_DMA, &queue->rt2x00dev->cap_flags))
-                rt2x00queue_align_frame(entry->skb);
+                rt2x00queue_align_frame(skb);
+
+        spin_lock(&queue->tx_lock);
+
+        if (unlikely(rt2x00queue_full(queue))) {
+                ERROR(queue->rt2x00dev,
+                      "Dropping frame due to full tx queue %d.\n", queue->qid);
+                ret = -ENOBUFS;
+                goto out;
+        }
+
+        entry = rt2x00queue_get_entry(queue, Q_INDEX);
+
+        if (unlikely(test_and_set_bit(ENTRY_OWNER_DEVICE_DATA,
+                                      &entry->flags))) {
+                ERROR(queue->rt2x00dev,
+                      "Arrived at non-free entry in the non-full queue %d.\n"
+                      "Please file bug report to %s.\n",
+                      queue->qid, DRV_PROJECT);
+                ret = -EINVAL;
+                goto out;
+        }
+
+        skbdesc->entry = entry;
+        entry->skb = skb;
 
         /*
          * It could be possible that the queue was corrupted and this