rt2x00: Simplify TXD handling of beacons.

The handling of tx descriptors for beacons can be simplified by updating
write_tx_desc implementations of each driver to write directly to the
queue entry descriptor instead of to a provided memory area.
This is also a preparation for further clean ups where descriptors are
properly reserved in the skb instead of fiddling with the skb data
pointer.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
index 55aa010..1be1d7d 100644
--- a/drivers/net/wireless/rt2x00/rt61pci.c
+++ b/drivers/net/wireless/rt2x00/rt61pci.c
@@ -1763,7 +1763,8 @@
 				  struct txentry_desc *txdesc)
 {
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
-	__le32 *txd = skbdesc->desc;
+	struct queue_entry_priv_pci *entry_priv = skbdesc->entry->priv_data;
+	__le32 *txd = entry_priv->desc;
 	u32 word;
 
 	/*
@@ -1842,6 +1843,13 @@
 			   test_bit(ENTRY_TXD_BURST, &txdesc->flags));
 	rt2x00_set_field32(&word, TXD_W0_CIPHER_ALG, txdesc->cipher);
 	rt2x00_desc_write(txd, 0, word);
+
+	/*
+	 * Register descriptor details in skb frame descriptor.
+	 */
+	skbdesc->desc = txd;
+	skbdesc->desc_len =
+		(txdesc->queue == QID_BEACON) ?  TXINFO_SIZE : TXD_DESC_SIZE;
 }
 
 /*
@@ -1851,7 +1859,7 @@
 				 struct txentry_desc *txdesc)
 {
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
-	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
+	struct queue_entry_priv_pci *entry_priv = entry->priv_data;
 	unsigned int beacon_base;
 	u32 reg;
 
@@ -1867,11 +1875,9 @@
 	 * Write entire beacon with descriptor to register.
 	 */
 	beacon_base = HW_BEACON_OFFSET(entry->entry_idx);
-	rt2x00pci_register_multiwrite(rt2x00dev,
-				      beacon_base,
-				      skbdesc->desc, skbdesc->desc_len);
-	rt2x00pci_register_multiwrite(rt2x00dev,
-				      beacon_base + skbdesc->desc_len,
+	rt2x00pci_register_multiwrite(rt2x00dev, beacon_base,
+				      entry_priv->desc, TXINFO_SIZE);
+	rt2x00pci_register_multiwrite(rt2x00dev, beacon_base + TXINFO_SIZE,
 				      entry->skb->data, entry->skb->len);
 
 	/*