Commit 6c17b77b authored by Seth Forshee's avatar Seth Forshee Committed by Johannes Berg
Browse files

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: default avatarSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent df15a6c4

include/net/mac80211.h

+4 −0
Original line number Diff line number Diff line
@@ -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),

net/mac80211/cfg.c

+2 −1
Original line number Diff line number Diff line
@@ -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;

net/mac80211/ieee80211_i.h

+1 −0
Original line number Diff line number Diff line
@@ -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

net/mac80211/mlme.c

+2 −1
Original line number Diff line number Diff line
@@ -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;

net/mac80211/offchannel.c

+10 −20
Original line number Diff line number Diff line
@@ -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))
@@ -133,13 +137,10 @@ 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);

	}

	}

	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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE