ath9k: fix an aggregation start related race condition

[deliverable/linux.git] / drivers / net / wireless / ath / ath9k / xmit.c

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 700ba8dee5a50d195882d6179ca6f2aad9f0b580..d629bfbdfab47bbe0182f0dc9133241a0e7b1cd0 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -120,26 +120,14 @@ static void ath_tx_queue_tid(struct ath_txq *txq, struct ath_atx_tid *tid)
        list_add_tail(&ac->list, &txq->axq_acq);
 }
 
-static void ath_tx_pause_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
-{
-       struct ath_txq *txq = &sc->tx.txq[tid->ac->qnum];
-
-       spin_lock_bh(&txq->axq_lock);
-       tid->paused++;
-       spin_unlock_bh(&txq->axq_lock);
-}
-
 static void ath_tx_resume_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
 {
        struct ath_txq *txq = &sc->tx.txq[tid->ac->qnum];
 
-       BUG_ON(tid->paused <= 0);
-       spin_lock_bh(&txq->axq_lock);
+       WARN_ON(!tid->paused);
 
-       tid->paused--;
-
-       if (tid->paused > 0)
-               goto unlock;
+       spin_lock_bh(&txq->axq_lock);
+       tid->paused = false;
 
        if (list_empty(&tid->buf_q))
                goto unlock;
@@ -157,15 +145,10 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
        struct list_head bf_head;
        INIT_LIST_HEAD(&bf_head);
 
-       BUG_ON(tid->paused <= 0);
-       spin_lock_bh(&txq->axq_lock);
+       WARN_ON(!tid->paused);
 
-       tid->paused--;
-
-       if (tid->paused > 0) {
-               spin_unlock_bh(&txq->axq_lock);
-               return;
-       }
+       spin_lock_bh(&txq->axq_lock);
+       tid->paused = false;
 
        while (!list_empty(&tid->buf_q)) {
                bf = list_first_entry(&tid->buf_q, struct ath_buf, list);
@@ -185,9 +168,9 @@ static void ath_tx_update_baw(struct ath_softc *sc, struct ath_atx_tid *tid,
        index  = ATH_BA_INDEX(tid->seq_start, seqno);
        cindex = (tid->baw_head + index) & (ATH_TID_MAX_BUFS - 1);
 
-       tid->tx_buf[cindex] = NULL;
+       __clear_bit(cindex, tid->tx_buf);
 
-       while (tid->baw_head != tid->baw_tail && !tid->tx_buf[tid->baw_head]) {
+       while (tid->baw_head != tid->baw_tail && !test_bit(tid->baw_head, tid->tx_buf)) {
                INCR(tid->seq_start, IEEE80211_SEQ_MAX);
                INCR(tid->baw_head, ATH_TID_MAX_BUFS);
        }
@@ -203,9 +186,7 @@ static void ath_tx_addto_baw(struct ath_softc *sc, struct ath_atx_tid *tid,
 
        index  = ATH_BA_INDEX(tid->seq_start, bf->bf_seqno);
        cindex = (tid->baw_head + index) & (ATH_TID_MAX_BUFS - 1);
-
-       BUG_ON(tid->tx_buf[cindex] != NULL);
-       tid->tx_buf[cindex] = bf;
+       __set_bit(cindex, tid->tx_buf);
 
        if (index >= ((tid->baw_tail - tid->baw_head) &
                (ATH_TID_MAX_BUFS - 1))) {
@@ -802,17 +783,23 @@ static void ath_tx_sched_aggr(struct ath_softc *sc, struct ath_txq *txq,
                 status != ATH_AGGR_BAW_CLOSED);
 }
 
-void ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
-                      u16 tid, u16 *ssn)
+int ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
+                     u16 tid, u16 *ssn)
 {
        struct ath_atx_tid *txtid;
        struct ath_node *an;
 
        an = (struct ath_node *)sta->drv_priv;
        txtid = ATH_AN_2_TID(an, tid);
+
+       if (txtid->state & (AGGR_CLEANUP | AGGR_ADDBA_COMPLETE))
+               return -EAGAIN;
+
        txtid->state |= AGGR_ADDBA_PROGRESS;
-       ath_tx_pause_tid(sc, txtid);
+       txtid->paused = true;
        *ssn = txtid->seq_start;
+
+       return 0;
 }
 
 void ath_tx_aggr_stop(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)
@@ -835,10 +822,9 @@ void ath_tx_aggr_stop(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)
                return;
        }
 
-       ath_tx_pause_tid(sc, txtid);
-
        /* drop all software retried frames and mark this TID */
        spin_lock_bh(&txq->axq_lock);
+       txtid->paused = true;
        while (!list_empty(&txtid->buf_q)) {
                bf = list_first_entry(&txtid->buf_q, struct ath_buf, list);
                if (!bf_isretried(bf)) {
@@ -1425,22 +1411,6 @@ static enum ath9k_pkt_type get_hw_packet_type(struct sk_buff *skb)
        return htype;
 }
 
-static int get_hw_crypto_keytype(struct sk_buff *skb)
-{
-       struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
-
-       if (tx_info->control.hw_key) {
-               if (tx_info->control.hw_key->alg == ALG_WEP)
-                       return ATH9K_KEY_TYPE_WEP;
-               else if (tx_info->control.hw_key->alg == ALG_TKIP)
-                       return ATH9K_KEY_TYPE_TKIP;
-               else if (tx_info->control.hw_key->alg == ALG_CCMP)
-                       return ATH9K_KEY_TYPE_AES;
-       }
-
-       return ATH9K_KEY_TYPE_CLEAR;
-}
-
 static void assign_aggr_tid_seqno(struct sk_buff *skb,
                                  struct ath_buf *bf)
 {
@@ -1679,7 +1649,7 @@ static int ath_tx_setup_buffer(struct ieee80211_hw *hw, struct ath_buf *bf,
                bf->bf_state.bfs_paprd_timestamp = jiffies;
        bf->bf_flags = setup_tx_flags(skb, use_ldpc);
 
-       bf->bf_keytype = get_hw_crypto_keytype(skb);
+       bf->bf_keytype = ath9k_cmn_get_hw_crypto_keytype(skb);
        if (bf->bf_keytype != ATH9K_KEY_TYPE_CLEAR) {
                bf->bf_frmlen += tx_info->control.hw_key->icv_len;
                bf->bf_keyix = tx_info->control.hw_key->hw_key_idx;