rt2x00: Split rt2x00lib_write_tx_desc()

Split rt2x00lib_write_tx_desc() up into a TX descriptor initializor
and TX descriptor writer.

This split is required to properly allow mac80211 to move its
tx_control structure into the skb->cb array.
The rt2x00queue_create_tx_descriptor() function will read all tx control
information and convert it into a rt2x00 TX descriptor information structure.
After that function is complete, we have all information we needed from the
tx control structure and are free to start writing into the skb->cb array
for our own purposes.
rt2x00queue_write_tx_descriptor() will be in charge of really sending
the TX descriptor to the hardware and kicking the TX queue.

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

1 files changed, 35 insertions, 7 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 6f7b34fac16c..9c186d79c11c 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -927,6 +927,41 @@ static inline u16 get_duration_res(const unsigned int size, const u8 rate)
 }
 
 /**
+ * rt2x00queue_create_tx_descriptor - Create TX descriptor from mac80211 input
+ * @entry: The entry which will be used to transfer the TX frame.
+ * @txdesc: rt2x00 TX descriptor which will be initialized by this function.
+ * @control: mac80211 TX control structure from where we read the information.
+ *
+ * This function will initialize the &struct txentry_desc based on information
+ * from mac80211. This descriptor can then be used by rt2x00lib and the drivers
+ * to correctly initialize the hardware descriptor.
+ * Note that before calling this function the skb->cb array must be untouched
+ * by rt2x00lib. Only after this function completes will it be save to
+ * overwrite the skb->cb information.
+ * The reason for this is that mac80211 writes its own tx information into
+ * the skb->cb array, and this function will use that information to initialize
+ * the &struct txentry_desc structure.
+ */
+void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
+                                      struct txentry_desc *txdesc,
+                                      struct ieee80211_tx_control *control);
+
+/**
+ * rt2x00queue_write_tx_descriptor - Write TX descriptor to hardware
+ * @entry: The entry which will be used to transfer the TX frame.
+ * @txdesc: TX descriptor which will be used to write hardware descriptor
+ *
+ * This function will write a TX descriptor initialized by
+ * &rt2x00queue_create_tx_descriptor to the hardware. After this call
+ * has completed the frame is now owned by the hardware, the hardware
+ * queue will have automatically be kicked unless this frame was generated
+ * by rt2x00lib, in which case the frame is "special" and must be kicked
+ * by the caller.
+ */
+void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
+                                     struct txentry_desc *txdesc);
+
+/**
  * rt2x00queue_get_queue - Convert queue index to queue pointer
  * @rt2x00dev: Pointer to &struct rt2x00_dev.
  * @queue: rt2x00 queue index (see &enum data_queue_qid).
@@ -964,13 +999,6 @@ void rt2x00lib_rxdone(struct queue_entry *entry,
                       struct rxdone_entry_desc *rxdesc);
 
 /*
- * TX descriptor initializer
- */
-void rt2x00lib_write_tx_desc(struct rt2x00_dev *rt2x00dev,
-                             struct sk_buff *skb,
-                             struct ieee80211_tx_control *control);
-
-/*
  * mac80211 handlers.
  */
 int rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb,