From: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
To: Felix Fietkau <nbd@openwrt.org>
Cc: <linux-wireless@vger.kernel.org>, <linville@tuxdriver.com>,
<rodrigue@qca.qualcomm.com>
Subject: Re: [PATCH] ath9k: fix tx locking issues
Date: Tue, 20 Dec 2011 10:19:09 +0530 [thread overview]
Message-ID: <4EF013C5.2080107@qca.qualcomm.com> (raw)
In-Reply-To: <1324309554-78839-1-git-send-email-nbd@openwrt.org>
Hi Felix,
thanks for fixing this!
thanks,
shafi
On Monday 19 December 2011 09:15 PM, Felix Fietkau wrote:
> The commit "ath9k: simplify tx locking" introduced a soft lockup triggered
> by mac80211 sending a BAR frame triggered by a driver call to
> ieee80211_tx_send_bar or ieee80211_tx_status.
> Fix these issues by queueing processed tx status skbs and submitting them
> to mac80211 outside of the lock.
>
> Signed-off-by: Felix Fietkau<nbd@openwrt.org>
> Signed-off-by: Mohammed Shafi Shajakhan<mohammed@qca.qualcomm.com>
> ---
> drivers/net/wireless/ath/ath9k/ath9k.h | 1 +
> drivers/net/wireless/ath/ath9k/xmit.c | 96 +++++++++++++++++++++-----------
> 2 files changed, 65 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
> index 130e5db..95276e9 100644
> --- a/drivers/net/wireless/ath/ath9k/ath9k.h
> +++ b/drivers/net/wireless/ath/ath9k/ath9k.h
> @@ -196,6 +196,7 @@ struct ath_txq {
> u8 txq_headidx;
> u8 txq_tailidx;
> int pending_frames;
> + struct sk_buff_head complete_q;
> };
>
> struct ath_atx_ac {
> diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
> index 23e80e6..60d372b 100644
> --- a/drivers/net/wireless/ath/ath9k/xmit.c
> +++ b/drivers/net/wireless/ath/ath9k/xmit.c
> @@ -104,6 +104,29 @@ static int ath_max_4ms_framelen[4][32] = {
> /* Aggregation logic */
> /*********************/
>
> +static void ath_txq_lock(struct ath_softc *sc, struct ath_txq *txq)
> +{
> + spin_lock_bh(&txq->axq_lock);
> +}
> +
> +static void ath_txq_unlock(struct ath_softc *sc, struct ath_txq *txq)
> +{
> + spin_unlock_bh(&txq->axq_lock);
> +}
> +
> +static void ath_txq_unlock_complete(struct ath_softc *sc, struct ath_txq *txq)
> +{
> + struct sk_buff_head q;
> + struct sk_buff *skb;
> +
> + __skb_queue_head_init(&q);
> + skb_queue_splice_init(&txq->complete_q,&q);
> + spin_unlock_bh(&txq->axq_lock);
> +
> + while ((skb = __skb_dequeue(&q)))
> + ieee80211_tx_status(sc->hw, skb);
> +}
> +
> static void ath_tx_queue_tid(struct ath_txq *txq, struct ath_atx_tid *tid)
> {
> struct ath_atx_ac *ac = tid->ac;
> @@ -130,7 +153,7 @@ static void ath_tx_resume_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
>
> WARN_ON(!tid->paused);
>
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
> tid->paused = false;
>
> if (skb_queue_empty(&tid->buf_q))
> @@ -139,7 +162,7 @@ static void ath_tx_resume_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
> ath_tx_queue_tid(txq, tid);
> ath_txq_schedule(sc, txq);
> unlock:
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock_complete(sc, txq);
> }
>
> static struct ath_frame_info *get_frame_info(struct sk_buff *skb)
> @@ -189,8 +212,11 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
> tid->state&= ~AGGR_CLEANUP;
> }
>
> - if (sendbar)
> + if (sendbar) {
> + ath_txq_unlock(sc, txq);
> ath_send_bar(tid, tid->seq_start);
> + ath_txq_lock(sc, txq);
> + }
> }
>
> static void ath_tx_update_baw(struct ath_softc *sc, struct ath_atx_tid *tid,
> @@ -554,13 +580,6 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
> bf = bf_next;
> }
>
> - if (bar_index>= 0) {
> - u16 bar_seq = ATH_BA_INDEX2SEQ(seq_first, bar_index);
> - ath_send_bar(tid, ATH_BA_INDEX2SEQ(seq_first, bar_index + 1));
> - if (BAW_WITHIN(tid->seq_start, tid->baw_size, bar_seq))
> - tid->bar_index = ATH_BA_INDEX(tid->seq_start, bar_seq);
> - }
> -
> /* prepend un-acked frames to the beginning of the pending frame queue */
> if (!skb_queue_empty(&bf_pending)) {
> if (an->sleeping)
> @@ -575,6 +594,17 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
> }
> }
>
> + if (bar_index>= 0) {
> + u16 bar_seq = ATH_BA_INDEX2SEQ(seq_first, bar_index);
> +
> + if (BAW_WITHIN(tid->seq_start, tid->baw_size, bar_seq))
> + tid->bar_index = ATH_BA_INDEX(tid->seq_start, bar_seq);
> +
> + ath_txq_unlock(sc, txq);
> + ath_send_bar(tid, ATH_BA_INDEX2SEQ(seq_first, bar_index + 1));
> + ath_txq_lock(sc, txq);
> + }
> +
> if (tid->state& AGGR_CLEANUP)
> ath_tx_flush_tid(sc, tid);
>
> @@ -1172,7 +1202,7 @@ void ath_tx_aggr_stop(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)
> return;
> }
>
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
> txtid->paused = true;
>
> /*
> @@ -1187,7 +1217,7 @@ void ath_tx_aggr_stop(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)
> txtid->state&= ~AGGR_ADDBA_COMPLETE;
>
> ath_tx_flush_tid(sc, txtid);
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock_complete(sc, txq);
> }
>
> void ath_tx_aggr_sleep(struct ieee80211_sta *sta, struct ath_softc *sc,
> @@ -1208,7 +1238,7 @@ void ath_tx_aggr_sleep(struct ieee80211_sta *sta, struct ath_softc *sc,
> ac = tid->ac;
> txq = ac->txq;
>
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
>
> buffered = !skb_queue_empty(&tid->buf_q);
>
> @@ -1220,7 +1250,7 @@ void ath_tx_aggr_sleep(struct ieee80211_sta *sta, struct ath_softc *sc,
> list_del(&ac->list);
> }
>
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock(sc, txq);
>
> ieee80211_sta_set_buffered(sta, tidno, buffered);
> }
> @@ -1239,7 +1269,7 @@ void ath_tx_aggr_wakeup(struct ath_softc *sc, struct ath_node *an)
> ac = tid->ac;
> txq = ac->txq;
>
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
> ac->clear_ps_filter = true;
>
> if (!skb_queue_empty(&tid->buf_q)&& !tid->paused) {
> @@ -1247,7 +1277,7 @@ void ath_tx_aggr_wakeup(struct ath_softc *sc, struct ath_node *an)
> ath_txq_schedule(sc, txq);
> }
>
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock_complete(sc, txq);
> }
> }
>
> @@ -1347,6 +1377,7 @@ struct ath_txq *ath_txq_setup(struct ath_softc *sc, int qtype, int subtype)
> txq->axq_qnum = axq_qnum;
> txq->mac80211_qnum = -1;
> txq->axq_link = NULL;
> + __skb_queue_head_init(&txq->complete_q);
> INIT_LIST_HEAD(&txq->axq_q);
> INIT_LIST_HEAD(&txq->axq_acq);
> spin_lock_init(&txq->axq_lock);
> @@ -1471,7 +1502,8 @@ static void ath_drain_txq_list(struct ath_softc *sc, struct ath_txq *txq,
> */
> void ath_draintxq(struct ath_softc *sc, struct ath_txq *txq, bool retry_tx)
> {
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
> +
> if (sc->sc_ah->caps.hw_caps& ATH9K_HW_CAP_EDMA) {
> int idx = txq->txq_tailidx;
>
> @@ -1492,7 +1524,7 @@ void ath_draintxq(struct ath_softc *sc, struct ath_txq *txq, bool retry_tx)
> if ((sc->sc_flags& SC_OP_TXAGGR)&& !retry_tx)
> ath_txq_drain_pending_buffers(sc, txq);
>
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock_complete(sc, txq);
> }
>
> bool ath_drain_all_txq(struct ath_softc *sc, bool retry_tx)
> @@ -1925,7 +1957,8 @@ int ath_tx_start(struct ieee80211_hw *hw, struct sk_buff *skb,
> */
>
> q = skb_get_queue_mapping(skb);
> - spin_lock_bh(&txq->axq_lock);
> +
> + ath_txq_lock(sc, txq);
> if (txq == sc->tx.txq_map[q]&&
> ++txq->pending_frames> ATH_MAX_QDEPTH&& !txq->stopped) {
> ieee80211_stop_queue(sc->hw, q);
> @@ -1934,7 +1967,7 @@ int ath_tx_start(struct ieee80211_hw *hw, struct sk_buff *skb,
>
> ath_tx_start_dma(sc, skb, txctl);
>
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock(sc, txq);
>
> return 0;
> }
> @@ -1946,7 +1979,6 @@ int ath_tx_start(struct ieee80211_hw *hw, struct sk_buff *skb,
> static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
> int tx_flags, struct ath_txq *txq)
> {
> - struct ieee80211_hw *hw = sc->hw;
> struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
> struct ath_common *common = ath9k_hw_common(sc->sc_ah);
> struct ieee80211_hdr * hdr = (struct ieee80211_hdr *)skb->data;
> @@ -1990,7 +2022,7 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
> }
> }
>
> - ieee80211_tx_status(hw, skb);
> + __skb_queue_tail(&txq->complete_q, skb);
> }
>
> static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf,
> @@ -2126,7 +2158,7 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
> txq->axq_qnum, ath9k_hw_gettxbuf(sc->sc_ah, txq->axq_qnum),
> txq->axq_link);
>
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
> for (;;) {
> if (work_pending(&sc->hw_reset_work))
> break;
> @@ -2185,7 +2217,7 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
>
> ath_tx_process_buffer(sc, txq,&ts, bf,&bf_head);
> }
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock_complete(sc, txq);
> }
>
> static void ath_tx_complete_poll_work(struct work_struct *work)
> @@ -2202,17 +2234,17 @@ static void ath_tx_complete_poll_work(struct work_struct *work)
> for (i = 0; i< ATH9K_NUM_TX_QUEUES; i++)
> if (ATH_TXQ_SETUP(sc, i)) {
> txq =&sc->tx.txq[i];
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
> if (txq->axq_depth) {
> if (txq->axq_tx_inprogress) {
> needreset = true;
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock(sc, txq);
> break;
> } else {
> txq->axq_tx_inprogress = true;
> }
> }
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock_complete(sc, txq);
> }
>
> if (needreset) {
> @@ -2270,10 +2302,10 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
>
> txq =&sc->tx.txq[ts.qid];
>
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
>
> if (list_empty(&txq->txq_fifo[txq->txq_tailidx])) {
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock(sc, txq);
> return;
> }
>
> @@ -2299,7 +2331,7 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
> }
>
> ath_tx_process_buffer(sc, txq,&ts, bf,&bf_head);
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock_complete(sc, txq);
> }
> }
>
> @@ -2437,7 +2469,7 @@ void ath_tx_node_cleanup(struct ath_softc *sc, struct ath_node *an)
> ac = tid->ac;
> txq = ac->txq;
>
> - spin_lock_bh(&txq->axq_lock);
> + ath_txq_lock(sc, txq);
>
> if (tid->sched) {
> list_del(&tid->list);
> @@ -2453,6 +2485,6 @@ void ath_tx_node_cleanup(struct ath_softc *sc, struct ath_node *an)
> tid->state&= ~AGGR_ADDBA_COMPLETE;
> tid->state&= ~AGGR_CLEANUP;
>
> - spin_unlock_bh(&txq->axq_lock);
> + ath_txq_unlock(sc, txq);
> }
> }
prev parent reply other threads:[~2011-12-20 4:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-19 15:45 [PATCH] ath9k: fix tx locking issues Felix Fietkau
2011-12-20 4:49 ` Mohammed Shafi Shajakhan [this message]
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