From 0ecfe806f146e0cb10c2c5abbb3bb4e91959e41a Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 9 Nov 2011 12:14:16 +0100 Subject: [PATCH] mac80211: fix race between connection monitor & suspend When the connection monitor timer fires right before suspend, the following will happen: timer fires -> monitor_work gets queued suspend calls ieee80211_sta_quiesce ieee80211_sta_quiesce: - deletes timer - cancels monitor_work synchronously, running it [note wrong order of these steps] monitor_work runs, re-arming the timer later, timer fires while system should be quiesced This causes a warning: WARNING: at net/mac80211/util.c:540 ieee80211_can_queue_work+0x35/0x40 [mac80211]() but is otherwise harmless. I'm not completely sure this is the scenario Thomas stumbled across, but it is the only way I can right now see the warning in a scenario like the one he reported. Reported-by: Thomas Meyer Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/mlme.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index d3b408cda08d..40db011da580 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2286,6 +2286,7 @@ void ieee80211_sta_quiesce(struct ieee80211_sub_if_data *sdata) cancel_work_sync(&ifmgd->request_smps_work); + cancel_work_sync(&ifmgd->monitor_work); cancel_work_sync(&ifmgd->beacon_connection_loss_work); if (del_timer_sync(&ifmgd->timer)) set_bit(TMR_RUNNING_TIMER, &ifmgd->timers_running); @@ -2294,7 +2295,6 @@ void ieee80211_sta_quiesce(struct ieee80211_sub_if_data *sdata) if (del_timer_sync(&ifmgd->chswitch_timer)) set_bit(TMR_RUNNING_CHANSW, &ifmgd->timers_running); - cancel_work_sync(&ifmgd->monitor_work); /* these will just be re-established on connection */ del_timer_sync(&ifmgd->conn_mon_timer); del_timer_sync(&ifmgd->bcn_mon_timer); -- GitLab