ath9k_htc: Handle TX queue overflow

Stop/restart TX queues when the internal SKB
queue is full. This helps handle TX better
under heavy load.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h
index 698e6f1..e09c6c2 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/htc.h
+++ b/drivers/net/wireless/ath/ath9k/htc.h
@@ -349,6 +349,9 @@ struct ath9k_htc_priv {
        struct sk_buff *beacon;
        spinlock_t beacon_lock;
 
+       bool tx_queues_stop;
+       spinlock_t tx_lock;
+
        struct ieee80211_vif *vif;
        unsigned int rxfilter;
        struct tasklet_struct wmi_tasklet;

diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_init.c b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
index 10c8760..3206eb0 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/htc_drv_init.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
@@ -449,6 +449,7 @@ static int ath9k_init_priv(struct ath9k_htc_priv *priv, u16 devid)
 
        spin_lock_init(&priv->wmi->wmi_lock);
        spin_lock_init(&priv->beacon_lock);
+       spin_lock_init(&priv->tx_lock);
        mutex_init(&priv->mutex);
        mutex_init(&priv->aggr_work.mutex);
        tasklet_init(&priv->wmi_tasklet, ath9k_wmi_tasklet,

diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_main.c b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
index 90b13ed..63f032d 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/htc_drv_main.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
@@ -994,7 +994,7 @@ static int ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
        struct ieee80211_hdr *hdr;
        struct ath9k_htc_priv *priv = hw->priv;
-       int padpos, padsize;
+       int padpos, padsize, ret;
 
        hdr = (struct ieee80211_hdr *) skb->data;
 
@@ -1008,8 +1008,19 @@ static int ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
                memmove(skb->data, skb->data + padsize, padpos);
        }
 
-       if (ath9k_htc_tx_start(priv, skb) != 0) {
-               ath_print(ath9k_hw_common(priv->ah), ATH_DBG_XMIT, "Tx failed");
+       ret = ath9k_htc_tx_start(priv, skb);
+       if (ret != 0) {
+               if (ret == -ENOMEM) {
+                       ath_print(ath9k_hw_common(priv->ah), ATH_DBG_XMIT,
+                                 "Stopping TX queues\n");
+                       ieee80211_stop_queues(hw);
+                       spin_lock_bh(&priv->tx_lock);
+                       priv->tx_queues_stop = true;
+                       spin_unlock_bh(&priv->tx_lock);
+               } else {
+                       ath_print(ath9k_hw_common(priv->ah), ATH_DBG_XMIT,
+                                 "Tx failed");
+               }
                goto fail_tx;
        }
 
@@ -1074,6 +1085,12 @@ static int ath9k_htc_start(struct ieee80211_hw *hw)
        priv->op_flags &= ~OP_INVALID;
        htc_start(priv->htc);
 
+       spin_lock_bh(&priv->tx_lock);
+       priv->tx_queues_stop = false;
+       spin_unlock_bh(&priv->tx_lock);
+
+       ieee80211_wake_queues(hw);
+
 mutex_unlock:
        mutex_unlock(&priv->mutex);
        return ret;

diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
index 8383656..befe574 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
@@ -226,6 +226,18 @@ void ath9k_tx_tasklet(unsigned long data)
                /* Send status to mac80211 */
                ieee80211_tx_status(priv->hw, skb);
        }
+
+       /* Wake TX queues if needed */
+       spin_lock_bh(&priv->tx_lock);
+       if (priv->tx_queues_stop) {
+               priv->tx_queues_stop = false;
+               spin_unlock_bh(&priv->tx_lock);
+               ath_print(ath9k_hw_common(priv->ah), ATH_DBG_XMIT,
+                         "Waking up TX queues\n");
+               ieee80211_wake_queues(priv->hw);
+               return;
+       }
+       spin_unlock_bh(&priv->tx_lock);
 }
 
 void ath9k_htc_txep(void *drv_priv, struct sk_buff *skb,