rtl8187: feedback transmitted packets using tx close descriptor for 8187B

Realtek 8187B has a receive command queue to feedback beacon interrupt
and transmitted packet status. Use it to feedback mac80211 about status
of transmitted packets. Unfortunately in the course of testing I found
that the sequence number reported by hardware includes entire sequence
control in a 12 bit only field, so a workaround is done to check only
lowest bits.

Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rtl818x/rtl8187.h b/drivers/net/wireless/rtl818x/rtl8187.h
index f09872e..c385407 100644
--- a/drivers/net/wireless/rtl818x/rtl8187.h
+++ b/drivers/net/wireless/rtl818x/rtl8187.h
@@ -113,6 +113,11 @@
 	u8 noise;
 	u8 slot_time;
 	u8 aifsn[4];
+	struct {
+		__le64 buf;
+		struct urb *urb;
+		struct sk_buff_head queue;
+	} b_tx_status;
 };
 
 void rtl8187_write_phy(struct ieee80211_hw *dev, u8 addr, u32 data);