From 08db9397c9ac522941775d5f7ff209188e4babda Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 1 Mar 2019 13:10:53 +0100 Subject: [PATCH] mac80211: backport tx queue start/stop fix Among other things, it fixes a race condition on calling ieee80211_restart_hw Signed-off-by: Felix Fietkau --- ...d-stop-start-logic-for-software-TXQs.patch | 272 ++++++++++++++++++ .../522-mac80211_configure_antenna_gain.patch | 2 +- 2 files changed, 273 insertions(+), 1 deletion(-) create mode 100644 package/kernel/mac80211/patches/398-mac80211-add-stop-start-logic-for-software-TXQs.patch diff --git a/package/kernel/mac80211/patches/398-mac80211-add-stop-start-logic-for-software-TXQs.patch b/package/kernel/mac80211/patches/398-mac80211-add-stop-start-logic-for-software-TXQs.patch new file mode 100644 index 0000000000..c85e5c6612 --- /dev/null +++ b/package/kernel/mac80211/patches/398-mac80211-add-stop-start-logic-for-software-TXQs.patch @@ -0,0 +1,272 @@ +From: Manikanta Pubbisetty +Date: Wed, 11 Jul 2018 00:12:53 +0530 +Subject: [PATCH] mac80211: add stop/start logic for software TXQs + +Sometimes, it is required to stop the transmissions momentarily and +resume it later; stopping the txqs becomes very critical in scenarios where +the packet transmission has to be ceased completely. For example, during +the hardware restart, during off channel operations, +when initiating CSA(upon detecting a radar on the DFS channel), etc. + +The TX queue stop/start logic in mac80211 works well in stopping the TX +when drivers make use of netdev queues, i.e, when Qdiscs in network layer +take care of traffic scheduling. Since the devices implementing +wake_tx_queue can run without Qdiscs, packets will be handed to mac80211 +directly without queueing them in the netdev queues. + +Also, mac80211 does not invoke any of the +netif_stop_*/netif_wake_* APIs if wake_tx_queue is implemented. +Since the queues are not stopped in this case, transmissions can continue +and this will impact negatively on the operation of the wireless device. + +For example, +During hardware restart, we stop the netdev queues so that packets are +not sent to the driver. Since ath10k implements wake_tx_queue, +TX queues will not be stopped and packets might reach the hardware while +it is restarting; this can make hardware unresponsive and the only +possible option for recovery is to reboot the entire system. + +There is another problem to this, it is observed that the packets +were sent on the DFS channel for a prolonged duration after radar +detection impacting the channel closing time. + +We can still invoke netif stop/wake APIs when wake_tx_queue is implemented +but this could lead to packet drops in network layer; adding stop/start +logic for software TXQs in mac80211 instead makes more sense; the change +proposed adds the same in mac80211. + +Signed-off-by: Manikanta Pubbisetty +Signed-off-by: Johannes Berg +--- + +--- a/include/net/mac80211.h ++++ b/include/net/mac80211.h +@@ -1453,6 +1453,8 @@ enum ieee80211_vif_flags { + * @drv_priv: data area for driver use, will always be aligned to + * sizeof(void \*). + * @txq: the multicast data TX queue (if driver uses the TXQ abstraction) ++ * @txqs_stopped: per AC flag to indicate that intermediate TXQs are stopped, ++ * protected by fq->lock. + */ + struct ieee80211_vif { + enum nl80211_iftype type; +@@ -1477,6 +1479,8 @@ struct ieee80211_vif { + + unsigned int probe_req_reg; + ++ bool txqs_stopped[IEEE80211_NUM_ACS]; ++ + /* must be last */ + u8 drv_priv[0] __aligned(sizeof(void *)); + }; +--- a/net/mac80211/ieee80211_i.h ++++ b/net/mac80211/ieee80211_i.h +@@ -816,6 +816,7 @@ enum txq_info_flags { + IEEE80211_TXQ_STOP, + IEEE80211_TXQ_AMPDU, + IEEE80211_TXQ_NO_AMSDU, ++ IEEE80211_TXQ_STOP_NETIF_TX, + }; + + /** +@@ -1223,6 +1224,7 @@ struct ieee80211_local { + + struct sk_buff_head pending[IEEE80211_MAX_QUEUES]; + struct tasklet_struct tx_pending_tasklet; ++ struct tasklet_struct wake_txqs_tasklet; + + atomic_t agg_queue_stop[IEEE80211_MAX_QUEUES]; + +@@ -2037,6 +2039,7 @@ void ieee80211_txq_purge(struct ieee8021 + struct txq_info *txqi); + void ieee80211_txq_remove_vlan(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata); ++void ieee80211_wake_txqs(unsigned long data); + void ieee80211_send_auth(struct ieee80211_sub_if_data *sdata, + u16 transaction, u16 auth_alg, u16 status, + const u8 *extra, size_t extra_len, const u8 *bssid, +--- a/net/mac80211/main.c ++++ b/net/mac80211/main.c +@@ -671,6 +671,10 @@ struct ieee80211_hw *ieee80211_alloc_hw_ + tasklet_init(&local->tx_pending_tasklet, ieee80211_tx_pending, + (unsigned long)local); + ++ if (ops->wake_tx_queue) ++ tasklet_init(&local->wake_txqs_tasklet, ieee80211_wake_txqs, ++ (unsigned long)local); ++ + tasklet_init(&local->tasklet, + ieee80211_tasklet_handler, + (unsigned long) local); +--- a/net/mac80211/tx.c ++++ b/net/mac80211/tx.c +@@ -3463,13 +3463,19 @@ struct sk_buff *ieee80211_tx_dequeue(str + struct ieee80211_tx_info *info; + struct ieee80211_tx_data tx; + ieee80211_tx_result r; +- struct ieee80211_vif *vif; ++ struct ieee80211_vif *vif = txq->vif; + + spin_lock_bh(&fq->lock); + +- if (test_bit(IEEE80211_TXQ_STOP, &txqi->flags)) ++ if (test_bit(IEEE80211_TXQ_STOP, &txqi->flags) || ++ test_bit(IEEE80211_TXQ_STOP_NETIF_TX, &txqi->flags)) + goto out; + ++ if (vif->txqs_stopped[ieee80211_ac_from_tid(txq->tid)]) { ++ set_bit(IEEE80211_TXQ_STOP_NETIF_TX, &txqi->flags); ++ goto out; ++ } ++ + /* Make sure fragments stay together. */ + skb = __skb_dequeue(&txqi->frags); + if (skb) +@@ -3565,6 +3571,7 @@ begin: + } + + IEEE80211_SKB_CB(skb)->control.vif = vif; ++ + out: + spin_unlock_bh(&fq->lock); + +--- a/net/mac80211/util.c ++++ b/net/mac80211/util.c +@@ -239,6 +239,99 @@ __le16 ieee80211_ctstoself_duration(stru + } + EXPORT_SYMBOL(ieee80211_ctstoself_duration); + ++static void __ieee80211_wake_txqs(struct ieee80211_sub_if_data *sdata, int ac) ++{ ++ struct ieee80211_local *local = sdata->local; ++ struct ieee80211_vif *vif = &sdata->vif; ++ struct fq *fq = &local->fq; ++ struct ps_data *ps = NULL; ++ struct txq_info *txqi; ++ struct sta_info *sta; ++ int i; ++ ++ spin_lock_bh(&fq->lock); ++ ++ if (sdata->vif.type == NL80211_IFTYPE_AP) ++ ps = &sdata->bss->ps; ++ ++ sdata->vif.txqs_stopped[ac] = false; ++ ++ list_for_each_entry_rcu(sta, &local->sta_list, list) { ++ if (sdata != sta->sdata) ++ continue; ++ ++ for (i = 0; i < ARRAY_SIZE(sta->sta.txq); i++) { ++ struct ieee80211_txq *txq = sta->sta.txq[i]; ++ ++ txqi = to_txq_info(txq); ++ ++ if (ac != txq->ac) ++ continue; ++ ++ if (!test_and_clear_bit(IEEE80211_TXQ_STOP_NETIF_TX, ++ &txqi->flags)) ++ continue; ++ ++ spin_unlock_bh(&fq->lock); ++ drv_wake_tx_queue(local, txqi); ++ spin_lock_bh(&fq->lock); ++ } ++ } ++ ++ if (!vif->txq) ++ goto out; ++ ++ txqi = to_txq_info(vif->txq); ++ ++ if (!test_and_clear_bit(IEEE80211_TXQ_STOP_NETIF_TX, &txqi->flags) || ++ (ps && atomic_read(&ps->num_sta_ps)) || ac != vif->txq->ac) ++ goto out; ++ ++ spin_unlock_bh(&fq->lock); ++ ++ drv_wake_tx_queue(local, txqi); ++ return; ++out: ++ spin_unlock_bh(&fq->lock); ++} ++ ++void ieee80211_wake_txqs(unsigned long data) ++{ ++ struct ieee80211_local *local = (struct ieee80211_local *)data; ++ struct ieee80211_sub_if_data *sdata; ++ int n_acs = IEEE80211_NUM_ACS; ++ unsigned long flags; ++ int i; ++ ++ rcu_read_lock(); ++ spin_lock_irqsave(&local->queue_stop_reason_lock, flags); ++ ++ if (local->hw.queues < IEEE80211_NUM_ACS) ++ n_acs = 1; ++ ++ for (i = 0; i < local->hw.queues; i++) { ++ if (local->queue_stop_reasons[i]) ++ continue; ++ ++ spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); ++ list_for_each_entry_rcu(sdata, &local->interfaces, list) { ++ int ac; ++ ++ for (ac = 0; ac < n_acs; ac++) { ++ int ac_queue = sdata->vif.hw_queue[ac]; ++ ++ if (ac_queue == i || ++ sdata->vif.cab_queue == i) ++ __ieee80211_wake_txqs(sdata, ac); ++ } ++ } ++ spin_lock_irqsave(&local->queue_stop_reason_lock, flags); ++ } ++ ++ spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); ++ rcu_read_unlock(); ++} ++ + void ieee80211_propagate_queue_wake(struct ieee80211_local *local, int queue) + { + struct ieee80211_sub_if_data *sdata; +@@ -307,6 +400,9 @@ static void __ieee80211_wake_queue(struc + rcu_read_unlock(); + } else + tasklet_schedule(&local->tx_pending_tasklet); ++ ++ if (local->ops->wake_tx_queue) ++ tasklet_schedule(&local->wake_txqs_tasklet); + } + + void ieee80211_wake_queue_by_reason(struct ieee80211_hw *hw, int queue, +@@ -350,9 +446,6 @@ static void __ieee80211_stop_queue(struc + if (__test_and_set_bit(reason, &local->queue_stop_reasons[queue])) + return; + +- if (local->ops->wake_tx_queue) +- return; +- + if (local->hw.queues < IEEE80211_NUM_ACS) + n_acs = 1; + +@@ -365,8 +458,15 @@ static void __ieee80211_stop_queue(struc + + for (ac = 0; ac < n_acs; ac++) { + if (sdata->vif.hw_queue[ac] == queue || +- sdata->vif.cab_queue == queue) +- netif_stop_subqueue(sdata->dev, ac); ++ sdata->vif.cab_queue == queue) { ++ if (!local->ops->wake_tx_queue) { ++ netif_stop_subqueue(sdata->dev, ac); ++ continue; ++ } ++ spin_lock(&local->fq.lock); ++ sdata->vif.txqs_stopped[ac] = true; ++ spin_unlock(&local->fq.lock); ++ } + } + } + rcu_read_unlock(); diff --git a/package/kernel/mac80211/patches/522-mac80211_configure_antenna_gain.patch b/package/kernel/mac80211/patches/522-mac80211_configure_antenna_gain.patch index b815f5f22a..8a149dcb83 100644 --- a/package/kernel/mac80211/patches/522-mac80211_configure_antenna_gain.patch +++ b/package/kernel/mac80211/patches/522-mac80211_configure_antenna_gain.patch @@ -87,7 +87,7 @@ CFG80211_TESTMODE_CMD(ieee80211_testmode_cmd) --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h -@@ -1348,6 +1348,7 @@ struct ieee80211_local { +@@ -1350,6 +1350,7 @@ struct ieee80211_local { int dynamic_ps_forced_timeout; int user_power_level; /* in dBm, for all interfaces */ -- 2.30.2