mac80211: make tx() operation return void

The return value of the tx operation is commonly
misused by drivers, leading to errors. All drivers
will drop frames if they fail to TX the frame, and
they must also properly manage the queues (if they
didn't, mac80211 would already warn).

Removing the ability for drivers to return a BUSY
value also allows significant cleanups of the TX
TX handling code in mac80211.

Note that this also fixes a bug in ath9k_htc, the
old "return -1" there was wrong.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Tested-by: Sedat Dilek <sedat.dilek@googlemail.com> [ath5k]
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com> [rt2x00]
Acked-by: Larry Finger <Larry.Finger@lwfinger.net> [b43, rtl8187, rtlwifi]
Acked-by: Luciano Coelho <coelho@ti.com> [wl12xx]
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rtl818x/rtl8180/dev.c b/drivers/net/wireless/rtl818x/rtl8180/dev.c
index b85debb..80db5ca 100644
--- a/drivers/net/wireless/rtl818x/rtl8180/dev.c
+++ b/drivers/net/wireless/rtl818x/rtl8180/dev.c
@@ -240,7 +240,7 @@
 	return IRQ_HANDLED;
 }
 
-static int rtl8180_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
+static void rtl8180_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 {
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
@@ -321,8 +321,6 @@
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	rtl818x_iowrite8(priv, &priv->map->TX_DMA_POLLING, (1 << (prio + 4)));
-
-	return 0;
 }
 
 void rtl8180_set_anaparam(struct rtl8180_priv *priv, u32 anaparam)
@@ -687,7 +685,6 @@
 	struct ieee80211_hw *dev = vif_priv->dev;
 	struct ieee80211_mgmt *mgmt;
 	struct sk_buff *skb;
-	int err = 0;
 
 	/* don't overflow the tx ring */
 	if (ieee80211_queue_stopped(dev, 0))
@@ -708,8 +705,7 @@
 	/* TODO: use actual beacon queue */
 	skb_set_queue_mapping(skb, 0);
 
-	err = rtl8180_tx(dev, skb);
-	WARN_ON(err);
+	rtl8180_tx(dev, skb);
 
 resched:
 	/*