From 6c17b77b67587b9f9e3070fb89fe98cef3187131 Mon Sep 17 00:00:00 2001 From: Seth Forshee Date: Mon, 11 Feb 2013 11:21:07 -0600 Subject: [PATCH] mac80211: Fix tx queue handling during scans Scans currently work by stopping the netdev tx queues but leaving the mac80211 queues active. This stops the flow of incoming packets while still allowing mac80211 to transmit nullfunc and probe request frames to facilitate scanning. However, the driver may try to wake the mac80211 queues while in this state, which will also wake the netdev queues. To prevent this, add a new queue stop reason, IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL, to be used when stopping the tx queues for off-channel operation. This prevents the netdev queues from waking when a driver wakes the mac80211 queues. This also stops all frames from being transmitted, even those meant to be sent off-channel. Add a new tx control flag, IEEE80211_TX_CTL_OFFCHAN_TX_OK, which allows frames to be transmitted when the queues are stopped only for the off-channel stop reason. Update all locations transmitting off-channel frames to use this flag. Signed-off-by: Seth Forshee Signed-off-by: Johannes Berg --- include/net/mac80211.h | 4 ++++ net/mac80211/cfg.c | 3 ++- net/mac80211/ieee80211_i.h | 1 + net/mac80211/mlme.c | 3 ++- net/mac80211/offchannel.c | 30 ++++++++++-------------------- net/mac80211/scan.c | 9 ++++++--- net/mac80211/tx.c | 15 +++++++++++++++ 7 files changed, 40 insertions(+), 25 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 86ad2c341525..0eaa9092364b 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -399,6 +399,9 @@ struct ieee80211_bss_conf { * @IEEE80211_TX_CTL_RATE_CTRL_PROBE: internal to mac80211, can be * set by rate control algorithms to indicate probe rate, will * be cleared for fragmented frames (except on the last fragment) + * @IEEE80211_TX_INTFL_OFFCHAN_TX_OK: Internal to mac80211. Used to indicate + * that a frame can be transmitted while the queues are stopped for + * off-channel operation. * @IEEE80211_TX_INTFL_NEED_TXPROCESSING: completely internal to mac80211, * used to indicate that a pending frame requires TX processing before * it can be sent out. @@ -464,6 +467,7 @@ enum mac80211_tx_control_flags { IEEE80211_TX_STAT_AMPDU = BIT(10), IEEE80211_TX_STAT_AMPDU_NO_BACK = BIT(11), IEEE80211_TX_CTL_RATE_CTRL_PROBE = BIT(12), + IEEE80211_TX_INTFL_OFFCHAN_TX_OK = BIT(13), IEEE80211_TX_INTFL_NEED_TXPROCESSING = BIT(14), IEEE80211_TX_INTFL_RETRIED = BIT(15), IEEE80211_TX_INTFL_DONT_ENCRYPT = BIT(16), diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 8f6b593a921f..e3dec80cf617 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -2749,7 +2749,8 @@ static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev, goto out_unlock; } - IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN; + IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN | + IEEE80211_TX_INTFL_OFFCHAN_TX_OK; if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL) IEEE80211_SKB_CB(skb)->hw_queue = local->hw.offchannel_tx_hw_queue; diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 5635dfc7da34..76cdcfcd614c 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -809,6 +809,7 @@ enum queue_stop_reason { IEEE80211_QUEUE_STOP_REASON_AGGREGATION, IEEE80211_QUEUE_STOP_REASON_SUSPEND, IEEE80211_QUEUE_STOP_REASON_SKB_ADD, + IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL, }; #ifdef CONFIG_MAC80211_LEDS diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 76cacdb062c8..efb22763d56d 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -685,7 +685,8 @@ void ieee80211_send_nullfunc(struct ieee80211_local *local, if (powersave) nullfunc->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM); - IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; + IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT | + IEEE80211_TX_INTFL_OFFCHAN_TX_OK; if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL | IEEE80211_STA_CONNECTION_POLL)) IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_USE_MINRATE; diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c index 82baf5b6ecf4..4c3ee3e8285c 100644 --- a/net/mac80211/offchannel.c +++ b/net/mac80211/offchannel.c @@ -113,6 +113,10 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local) * notify the AP about us leaving the channel and stop all * STA interfaces. */ + + ieee80211_stop_queues_by_reason(&local->hw, + IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL); + mutex_lock(&local->iflist_mtx); list_for_each_entry(sdata, &local->interfaces, list) { if (!ieee80211_sdata_running(sdata)) @@ -133,12 +137,9 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local) sdata, BSS_CHANGED_BEACON_ENABLED); } - if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { - netif_tx_stop_all_queues(sdata->dev); - if (sdata->vif.type == NL80211_IFTYPE_STATION && - sdata->u.mgd.associated) - ieee80211_offchannel_ps_enable(sdata); - } + if (sdata->vif.type == NL80211_IFTYPE_STATION && + sdata->u.mgd.associated) + ieee80211_offchannel_ps_enable(sdata); } mutex_unlock(&local->iflist_mtx); } @@ -166,20 +167,6 @@ void ieee80211_offchannel_return(struct ieee80211_local *local) sdata->u.mgd.associated) ieee80211_offchannel_ps_disable(sdata); - if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { - /* - * This may wake up queues even though the driver - * currently has them stopped. This is not very - * likely, since the driver won't have gotten any - * (or hardly any) new packets while we weren't - * on the right channel, and even if it happens - * it will at most lead to queueing up one more - * packet per queue in mac80211 rather than on - * the interface qdisc. - */ - netif_tx_wake_all_queues(sdata->dev); - } - if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state)) { sdata->vif.bss_conf.enable_beacon = true; @@ -188,6 +175,9 @@ void ieee80211_offchannel_return(struct ieee80211_local *local) } } mutex_unlock(&local->iflist_mtx); + + ieee80211_wake_queues_by_reason(&local->hw, + IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL); } void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc) diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index edd47d9acb99..d9e2df96f676 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -382,6 +382,11 @@ static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, int i; struct ieee80211_sub_if_data *sdata; enum ieee80211_band band = local->hw.conf.channel->band; + u32 tx_flags; + + tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; + if (local->scan_req->no_cck) + tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; sdata = rcu_dereference_protected(local->scan_sdata, lockdep_is_held(&local->mtx)); @@ -393,9 +398,7 @@ static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, local->scan_req->ssids[i].ssid_len, local->scan_req->ie, local->scan_req->ie_len, local->scan_req->rates[band], false, - local->scan_req->no_cck ? - IEEE80211_TX_CTL_NO_CCK_RATE : 0, - local->hw.conf.channel, true); + tx_flags, local->hw.conf.channel, true); /* * After sending probe requests, wait for probe responses diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 2ef0e19b06bb..f476aa6a771d 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1230,6 +1230,21 @@ static bool ieee80211_tx_frags(struct ieee80211_local *local, spin_lock_irqsave(&local->queue_stop_reason_lock, flags); if (local->queue_stop_reasons[q] || (!txpending && !skb_queue_empty(&local->pending[q]))) { + if (unlikely(info->flags & + IEEE80211_TX_INTFL_OFFCHAN_TX_OK && + local->queue_stop_reasons[q] & + ~BIT(IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL))) { + /* + * Drop off-channel frames if queues are stopped + * for any reason other than off-channel + * operation. Never queue them. + */ + spin_unlock_irqrestore( + &local->queue_stop_reason_lock, flags); + ieee80211_purge_tx_queue(&local->hw, skbs); + return true; + } + /* * Since queue is stopped, queue up frames for later * transmission from the tx-pending tasklet when the -- 2.20.1