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authorJohannes Berg <johannes.berg@intel.com>2010-08-27 13:45:28 +0200
committerJohn W. Linville <linville@tuxdriver.com>2010-08-27 13:53:31 -0400
commit5b714c6a3753dad0798a70a049e15c7f6bc9446b (patch)
tree39345981014b14e881cbfbef87a4a3a74469fada
parentc35d02705e9c2db90a89b29142046b4ffd5a76e5 (diff)
mac80211: fix offchannel queue stopmaster-2010-08-27
Somebody noticed this problem, and I outlined to them how to fix it, but haven't heard back from them. So while I was adding the state field I figured I could use it to fix it. The problem, as I understand it, is that when we go offchannel while the driver has a queue stopped, the driver will likely start draining the queue and then enable it while offchannel. This in turn will enable the interface queue, and that leads to transmitting data frames on the wrong channel. Fix this by keeping track of offchannel status per interface, and not enabling the interface queues on interfaces that are offchannel when the driver enables a queue. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--net/mac80211/ieee80211_i.h3
-rw-r--r--net/mac80211/offchannel.c19
-rw-r--r--net/mac80211/util.c5
3 files changed, 24 insertions, 3 deletions
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index d529bd5eab4..9af50fbcd48 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -477,9 +477,12 @@ enum ieee80211_sub_if_data_flags {
* @SDATA_STATE_RUNNING: virtual interface is up & running; this
* mirrors netif_running() but is separate for interface type
* change handling while the interface is up
+ * @SDATA_STATE_OFFCHANNEL: This interface is currently in offchannel
+ * mode, so queues are stopped
*/
enum ieee80211_sdata_state_bits {
SDATA_STATE_RUNNING,
+ SDATA_STATE_OFFCHANNEL,
};
struct ieee80211_sub_if_data {
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index c36b1911987..eeacaa59380 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -112,8 +112,10 @@ void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
* used from user space controlled off-channel operations.
*/
if (sdata->vif.type != NL80211_IFTYPE_STATION &&
- sdata->vif.type != NL80211_IFTYPE_MONITOR)
+ sdata->vif.type != NL80211_IFTYPE_MONITOR) {
+ set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
netif_tx_stop_all_queues(sdata->dev);
+ }
}
mutex_unlock(&local->iflist_mtx);
}
@@ -131,6 +133,7 @@ void ieee80211_offchannel_stop_station(struct ieee80211_local *local)
continue;
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+ set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
netif_tx_stop_all_queues(sdata->dev);
if (sdata->u.mgd.associated)
ieee80211_offchannel_ps_enable(sdata);
@@ -155,8 +158,20 @@ void ieee80211_offchannel_return(struct ieee80211_local *local,
ieee80211_offchannel_ps_disable(sdata);
}
- if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
+ if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
+ clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
+ /*
+ * 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);
+ }
/* re-enable beaconing */
if (enable_beaconing &&
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index d38b3767e8c..bd40b11d5ab 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -283,8 +283,11 @@ static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
if (skb_queue_empty(&local->pending[queue])) {
rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list)
+ list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+ if (test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))
+ continue;
netif_wake_subqueue(sdata->dev, queue);
+ }
rcu_read_unlock();
} else
tasklet_schedule(&local->tx_pending_tasklet);