ath9k: Restart xmit logic in xmit watchdog.

The system can get into a state where the xmit queue
is stopped, but there are no packets pending, so
the queue will not be restarted.

Add logic to the xmit watchdog to attempt to restart
the xmit logic if this situation is detected.

Example 'dmesg' output:

ath: txq: f4e723e0 axq_qnum: 2, mac80211_qnum: 2 axq_link: f4e996c8 pending frames: 1 axq_acq empty: 1 stopped: 0 axq_depth: 0  Attempting to restart tx logic.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index d4640117fa8ccd04b3d2a5126655770713f6f119..dab0271f1c1ae2d30d460df2b1e45d0e7347ca50 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -184,7 +184,8 @@ enum ATH_AGGR_STATUS {
 
 #define ATH_TXFIFO_DEPTH 8
 struct ath_txq {
-       u32 axq_qnum;
+       int mac80211_qnum; /* mac80211 queue number, -1 means not mac80211 Q */
+       u32 axq_qnum; /* ath9k hardware queue number */
        u32 *axq_link;
        struct list_head axq_q;
        spinlock_t axq_lock;
@@ -280,6 +281,11 @@ struct ath_tx_control {
 #define ATH_TX_XRETRY       0x02
 #define ATH_TX_BAR          0x04
 
+/**
+ * @txq_map:  Index is mac80211 queue number.  This is
+ *  not necessarily the same as the hardware queue number
+ *  (axq_qnum).
+ */
 struct ath_tx {
        u16 seq_no;
        u32 txqsetup;
@@ -643,6 +649,7 @@ struct ath_softc {
        struct ath9k_debug debug;
        spinlock_t nodes_lock;
        struct list_head nodes; /* basically, stations */
+       unsigned int tx_complete_poll_work_seen;
 #endif
        struct ath_beacon_config cur_beacon_conf;
        struct delayed_work tx_complete_work;

diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index 9e009ccd006941b3debb68e7635ec75a9dde215e..b0cb792d38ca90f9b76b5e0b881b19a38a64908a 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -629,9 +629,11 @@ static ssize_t read_file_xmit(struct file *file, char __user *user_buf,
        if (buf == NULL)
                return -ENOMEM;
 
-       len += sprintf(buf, "Num-Tx-Queues: %i  tx-queues-setup: 0x%x\n"
+       len += sprintf(buf, "Num-Tx-Queues: %i  tx-queues-setup: 0x%x"
+                      " poll-work-seen: %u\n"
                       "%30s %10s%10s%10s\n\n",
                       ATH9K_NUM_TX_QUEUES, sc->tx.txqsetup,
+                      sc->tx_complete_poll_work_seen,
                       "BE", "BK", "VI", "VO");
 
        PR("MPDUs Queued:    ", queued);

diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 59c01ca4379ee9137d08226145a272bf5c755116..5279653c90c7f28bf28cb8f8af374609ecc751a7 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -442,9 +442,10 @@ static int ath9k_init_queues(struct ath_softc *sc)
        sc->config.cabqReadytime = ATH_CABQ_READY_TIME;
        ath_cabq_update(sc);
 
-       for (i = 0; i < WME_NUM_AC; i++)
+       for (i = 0; i < WME_NUM_AC; i++) {
                sc->tx.txq_map[i] = ath_txq_setup(sc, ATH9K_TX_QUEUE_DATA, i);
-
+               sc->tx.txq_map[i]->mac80211_qnum = i;
+       }
        return 0;
 }
 

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index a83f2c54508ce1d8ffe520146112d5774a11cbca..2ad732d36f86e2e7cb2ca5062e59f6464c622982 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -945,7 +945,7 @@ struct ath_txq *ath_txq_setup(struct ath_softc *sc, int qtype, int subtype)
                [WME_AC_VI] = ATH_TXQ_AC_VI,
                [WME_AC_VO] = ATH_TXQ_AC_VO,
        };
-       int qnum, i;
+       int axq_qnum, i;
 
        memset(&qi, 0, sizeof(qi));
        qi.tqi_subtype = subtype_txq_to_hwq[subtype];
@@ -979,24 +979,25 @@ struct ath_txq *ath_txq_setup(struct ath_softc *sc, int qtype, int subtype)
                        qi.tqi_qflags = TXQ_FLAG_TXEOLINT_ENABLE |
                                        TXQ_FLAG_TXDESCINT_ENABLE;
        }
-       qnum = ath9k_hw_setuptxqueue(ah, qtype, &qi);
-       if (qnum == -1) {
+       axq_qnum = ath9k_hw_setuptxqueue(ah, qtype, &qi);
+       if (axq_qnum == -1) {
                /*
                 * NB: don't print a message, this happens
                 * normally on parts with too few tx queues
                 */
                return NULL;
        }
-       if (qnum >= ARRAY_SIZE(sc->tx.txq)) {
+       if (axq_qnum >= ARRAY_SIZE(sc->tx.txq)) {
                ath_err(common, "qnum %u out of range, max %zu!\n",
-                       qnum, ARRAY_SIZE(sc->tx.txq));
-               ath9k_hw_releasetxqueue(ah, qnum);
+                       axq_qnum, ARRAY_SIZE(sc->tx.txq));
+               ath9k_hw_releasetxqueue(ah, axq_qnum);
                return NULL;
        }
-       if (!ATH_TXQ_SETUP(sc, qnum)) {
-               struct ath_txq *txq = &sc->tx.txq[qnum];
+       if (!ATH_TXQ_SETUP(sc, axq_qnum)) {
+               struct ath_txq *txq = &sc->tx.txq[axq_qnum];
 
-               txq->axq_qnum = qnum;
+               txq->axq_qnum = axq_qnum;
+               txq->mac80211_qnum = -1;
                txq->axq_link = NULL;
                INIT_LIST_HEAD(&txq->axq_q);
                INIT_LIST_HEAD(&txq->axq_acq);
@@ -1004,14 +1005,14 @@ struct ath_txq *ath_txq_setup(struct ath_softc *sc, int qtype, int subtype)
                txq->axq_depth = 0;
                txq->axq_ampdu_depth = 0;
                txq->axq_tx_inprogress = false;
-               sc->tx.txqsetup |= 1<<qnum;
+               sc->tx.txqsetup |= 1<<axq_qnum;
 
                txq->txq_headidx = txq->txq_tailidx = 0;
                for (i = 0; i < ATH_TXFIFO_DEPTH; i++)
                        INIT_LIST_HEAD(&txq->txq_fifo[i]);
                INIT_LIST_HEAD(&txq->txq_fifo_pending);
        }
-       return &sc->tx.txq[qnum];
+       return &sc->tx.txq[axq_qnum];
 }
 
 int ath_txq_update(struct ath_softc *sc, int qnum,
@@ -1973,17 +1974,16 @@ static void ath_tx_rc_status(struct ath_buf *bf, struct ath_tx_status *ts,
        tx_info->status.rates[tx_rateindex].count = ts->ts_longretry + 1;
 }
 
-static void ath_wake_mac80211_queue(struct ath_softc *sc, int qnum)
+/* Has no locking.  Must hold spin_lock_bh(&txq->axq_lock)
+ * before calling this.
+ */
+static void __ath_wake_mac80211_queue(struct ath_softc *sc, struct ath_txq *txq)
 {
-       struct ath_txq *txq;
-
-       txq = sc->tx.txq_map[qnum];
-       spin_lock_bh(&txq->axq_lock);
-       if (txq->stopped && txq->pending_frames < ATH_MAX_QDEPTH) {
-               if (ath_mac80211_start_queue(sc, qnum))
+       if (txq->mac80211_qnum >= 0 &&
+           txq->stopped && txq->pending_frames < ATH_MAX_QDEPTH) {
+               if (ath_mac80211_start_queue(sc, txq->mac80211_qnum))
                        txq->stopped = 0;
        }
-       spin_unlock_bh(&txq->axq_lock);
 }
 
 static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
@@ -2086,10 +2086,9 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
                else
                        ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, txok, 0);
 
-               if (txq == sc->tx.txq_map[qnum])
-                       ath_wake_mac80211_queue(sc, qnum);
-
                spin_lock_bh(&txq->axq_lock);
+               __ath_wake_mac80211_queue(sc, txq);
+
                if (sc->sc_flags & SC_OP_TXAGGR)
                        ath_txq_schedule(sc, txq);
                spin_unlock_bh(&txq->axq_lock);
@@ -2103,6 +2102,9 @@ static void ath_tx_complete_poll_work(struct work_struct *work)
        struct ath_txq *txq;
        int i;
        bool needreset = false;
+#ifdef CONFIG_ATH9K_DEBUGFS
+       sc->tx_complete_poll_work_seen++;
+#endif
 
        for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++)
                if (ATH_TXQ_SETUP(sc, i)) {
@@ -2116,6 +2118,34 @@ static void ath_tx_complete_poll_work(struct work_struct *work)
                                } else {
                                        txq->axq_tx_inprogress = true;
                                }
+                       } else {
+                               /* If the queue has pending buffers, then it
+                                * should be doing tx work (and have axq_depth).
+                                * Shouldn't get to this state I think..but
+                                * we do.
+                                */
+                               if (!(sc->sc_flags & (SC_OP_OFFCHANNEL)) &&
+                                   (txq->pending_frames > 0 ||
+                                    !list_empty(&txq->axq_acq) ||
+                                    txq->stopped)) {
+                                       ath_err(ath9k_hw_common(sc->sc_ah),
+                                               "txq: %p axq_qnum: %u,"
+                                               " mac80211_qnum: %i"
+                                               " axq_link: %p"
+                                               " pending frames: %i"
+                                               " axq_acq empty: %i"
+                                               " stopped: %i"
+                                               " axq_depth: 0  Attempting to"
+                                               " restart tx logic.\n",
+                                               txq, txq->axq_qnum,
+                                               txq->mac80211_qnum,
+                                               txq->axq_link,
+                                               txq->pending_frames,
+                                               list_empty(&txq->axq_acq),
+                                               txq->stopped);
+                                       __ath_wake_mac80211_queue(sc, txq);
+                                       ath_txq_schedule(sc, txq);
+                               }
                        }
                        spin_unlock_bh(&txq->axq_lock);
                }
@@ -2212,10 +2242,9 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
                        ath_tx_complete_buf(sc, bf, txq, &bf_head,
                                            &txs, txok, 0);
 
-               if (txq == sc->tx.txq_map[qnum])
-                       ath_wake_mac80211_queue(sc, qnum);
-
                spin_lock_bh(&txq->axq_lock);
+               __ath_wake_mac80211_queue(sc, txq);
+
                if (!list_empty(&txq->txq_fifo_pending)) {
                        INIT_LIST_HEAD(&bf_head);
                        bf = list_first_entry(&txq->txq_fifo_pending,