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>

9 files changed, 18 insertions, 24 deletions

diff --git a/drivers/net/wireless/ath/ar9170/ar9170.h b/drivers/net/wireless/ath/ar9170/ar9170.h
index 4f845f80c098..371e4ce49528 100644
--- a/drivers/net/wireless/ath/ar9170/ar9170.h
+++ b/drivers/net/wireless/ath/ar9170/ar9170.h
@@ -224,7 +224,7 @@ void ar9170_handle_command_response(struct ar9170 *ar, void *buf, u32 len);
 int ar9170_nag_limiter(struct ar9170 *ar);
 
 /* MAC */
-int ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb);
+void ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb);
 int ar9170_init_mac(struct ar9170 *ar);
 int ar9170_set_qos(struct ar9170 *ar);
 int ar9170_update_multicast(struct ar9170 *ar, const u64 mc_hast);
diff --git a/drivers/net/wireless/ath/ar9170/main.c b/drivers/net/wireless/ath/ar9170/main.c
index a9111e1161fd..b761fec0d721 100644
--- a/drivers/net/wireless/ath/ar9170/main.c
+++ b/drivers/net/wireless/ath/ar9170/main.c
@@ -1475,7 +1475,7 @@ static void ar9170_tx(struct ar9170 *ar)
 				     msecs_to_jiffies(AR9170_JANITOR_DELAY));
 }
 
-int ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
+void ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
 	struct ar9170 *ar = hw->priv;
 	struct ieee80211_tx_info *info;
@@ -1493,11 +1493,10 @@ int ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 	skb_queue_tail(&ar->tx_pending[queue], skb);
 
 	ar9170_tx(ar);
-	return NETDEV_TX_OK;
+	return;
 
 err_free:
 	dev_kfree_skb_any(skb);
-	return NETDEV_TX_OK;
 }
 
 static int ar9170_op_add_interface(struct ieee80211_hw *hw,
diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
index 70abb61e9eff..0ee54eb333de 100644
--- a/drivers/net/wireless/ath/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
@@ -1164,8 +1164,8 @@ struct ath5k_txq;
 
 void set_beacon_filter(struct ieee80211_hw *hw, bool enable);
 bool ath_any_vif_assoc(struct ath5k_softc *sc);
-int ath5k_tx_queue(struct ieee80211_hw *hw, struct sk_buff *skb,
-		   struct ath5k_txq *txq);
+void ath5k_tx_queue(struct ieee80211_hw *hw, struct sk_buff *skb,
+		    struct ath5k_txq *txq);
 int ath5k_init_hw(struct ath5k_softc *sc);
 int ath5k_stop_hw(struct ath5k_softc *sc);
 void ath5k_mode_setup(struct ath5k_softc *sc, struct ieee80211_vif *vif);
diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index 80d9cf0c4cd2..91411e9b4b68 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -1518,7 +1518,7 @@ unlock:
 * TX Handling *
 \*************/
 
-int
+void
 ath5k_tx_queue(struct ieee80211_hw *hw, struct sk_buff *skb,
 	       struct ath5k_txq *txq)
 {
@@ -1567,11 +1567,10 @@ ath5k_tx_queue(struct ieee80211_hw *hw, struct sk_buff *skb,
 		spin_unlock_irqrestore(&sc->txbuflock, flags);
 		goto drop_packet;
 	}
-	return NETDEV_TX_OK;
+	return;
 
 drop_packet:
 	dev_kfree_skb_any(skb);
-	return NETDEV_TX_OK;
 }
 
 static void
diff --git a/drivers/net/wireless/ath/ath5k/mac80211-ops.c b/drivers/net/wireless/ath/ath5k/mac80211-ops.c
index a60a726a140c..1fbe3c0b9f08 100644
--- a/drivers/net/wireless/ath/ath5k/mac80211-ops.c
+++ b/drivers/net/wireless/ath/ath5k/mac80211-ops.c
@@ -52,7 +52,7 @@ extern int ath5k_modparam_nohwcrypt;
 * Mac80211 functions *
 \********************/
 
-static int
+static void
 ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
 	struct ath5k_softc *sc = hw->priv;
@@ -60,10 +60,10 @@ ath5k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 
 	if (WARN_ON(qnum >= sc->ah->ah_capabilities.cap_queues.q_tx_num)) {
 		dev_kfree_skb_any(skb);
-		return 0;
+		return;
 	}
 
-	return ath5k_tx_queue(hw, skb, &sc->txqs[qnum]);
+	ath5k_tx_queue(hw, skb, &sc->txqs[qnum]);
 }
 
 
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_main.c b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
index 7367d6c1c649..71adab34006c 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_main.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
@@ -1036,7 +1036,7 @@ set_timer:
 /* mac80211 Callbacks */
 /**********************/
 
-static int ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
+static void ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
 	struct ieee80211_hdr *hdr;
 	struct ath9k_htc_priv *priv = hw->priv;
@@ -1049,7 +1049,7 @@ static int ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 	padsize = padpos & 3;
 	if (padsize && skb->len > padpos) {
 		if (skb_headroom(skb) < padsize)
-			return -1;
+			goto fail_tx;
 		skb_push(skb, padsize);
 		memmove(skb->data, skb->data + padsize, padpos);
 	}
@@ -1070,11 +1070,10 @@ static int ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 		goto fail_tx;
 	}
 
-	return 0;
+	return;
 
 fail_tx:
 	dev_kfree_skb_any(skb);
-	return 0;
 }
 
 static int ath9k_htc_start(struct ieee80211_hw *hw)
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index a71550049d84..39a72ae80970 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1142,8 +1142,7 @@ mutex_unlock:
 	return r;
 }
 
-static int ath9k_tx(struct ieee80211_hw *hw,
-		    struct sk_buff *skb)
+static void ath9k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
 	struct ath_softc *sc = hw->priv;
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
@@ -1200,10 +1199,9 @@ static int ath9k_tx(struct ieee80211_hw *hw,
 		goto exit;
 	}
 
-	return 0;
+	return;
 exit:
 	dev_kfree_skb_any(skb);
-	return 0;
 }
 
 static void ath9k_stop(struct ieee80211_hw *hw)
diff --git a/drivers/net/wireless/ath/carl9170/carl9170.h b/drivers/net/wireless/ath/carl9170/carl9170.h
index 420d437f9580..c6a5fae634a0 100644
--- a/drivers/net/wireless/ath/carl9170/carl9170.h
+++ b/drivers/net/wireless/ath/carl9170/carl9170.h
@@ -534,7 +534,7 @@ void carl9170_rx(struct ar9170 *ar, void *buf, unsigned int len);
 void carl9170_handle_command_response(struct ar9170 *ar, void *buf, u32 len);
 
 /* TX */
-int carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb);
+void carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb);
 void carl9170_tx_janitor(struct work_struct *work);
 void carl9170_tx_process_status(struct ar9170 *ar,
 				const struct carl9170_rsp *cmd);
diff --git a/drivers/net/wireless/ath/carl9170/tx.c b/drivers/net/wireless/ath/carl9170/tx.c
index 6f41e21d3a1c..0ef70b6fc512 100644
--- a/drivers/net/wireless/ath/carl9170/tx.c
+++ b/drivers/net/wireless/ath/carl9170/tx.c
@@ -1339,7 +1339,7 @@ err_unlock_rcu:
 	return false;
 }
 
-int carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
+void carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
 	struct ar9170 *ar = hw->priv;
 	struct ieee80211_tx_info *info;
@@ -1373,12 +1373,11 @@ int carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 	}
 
 	carl9170_tx(ar);
-	return NETDEV_TX_OK;
+	return;
 
 err_free:
 	ar->tx_dropped++;
 	dev_kfree_skb_any(skb);
-	return NETDEV_TX_OK;
 }
 
 void carl9170_tx_scheduler(struct ar9170 *ar)