From 4a199068230bd8074f2e39025a2216390ea5b829 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 26 Apr 2017 10:58:53 +0300 Subject: mac80211: disentangle iflist_mtx and chanctx_mtx At least on iwlwifi, sometimes lockdep complains that we can lock chanctx_mtx -> mvm.mutex -> iflist_mtx (due to iterate_interfaces) and iflist_mtx -> chanctx_mtx Remove the latter dependency in mac80211 by using the RTNL that we already hold in one case, and can relatively easily achieve in the other case. Signed-off-by: Johannes Berg --- net/mac80211/util.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net/mac80211/util.c') diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 7a37ce78bb38..37dad3dd6bac 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -2791,8 +2791,10 @@ void ieee80211_dfs_cac_cancel(struct ieee80211_local *local) struct ieee80211_sub_if_data *sdata; struct cfg80211_chan_def chandef; + /* for interface list, to avoid linking iflist_mtx and chanctx_mtx */ + ASSERT_RTNL(); + mutex_lock(&local->mtx); - mutex_lock(&local->iflist_mtx); list_for_each_entry(sdata, &local->interfaces, list) { /* it might be waiting for the local->mtx, but then * by the time it gets it, sdata->wdev.cac_started @@ -2809,7 +2811,6 @@ void ieee80211_dfs_cac_cancel(struct ieee80211_local *local) GFP_KERNEL); } } - mutex_unlock(&local->iflist_mtx); mutex_unlock(&local->mtx); } @@ -2831,7 +2832,9 @@ void ieee80211_dfs_radar_detected_work(struct work_struct *work) } mutex_unlock(&local->chanctx_mtx); + rtnl_lock(); ieee80211_dfs_cac_cancel(local); + rtnl_unlock(); if (num_chanctx > 1) /* XXX: multi-channel is not supported yet */ @@ -2846,7 +2849,7 @@ void ieee80211_radar_detected(struct ieee80211_hw *hw) trace_api_radar_detected(local); - ieee80211_queue_work(hw, &local->radar_detected_work); + schedule_work(&local->radar_detected_work); } EXPORT_SYMBOL(ieee80211_radar_detected); -- cgit v1.2.3