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authorJohannes Berg <johannes.berg@intel.com>2017-04-26 10:58:53 +0300
committerJohannes Berg <johannes.berg@intel.com>2017-04-27 00:17:44 +0300
commit4a199068230bd8074f2e39025a2216390ea5b829 (patch)
tree88af85b1f1511f285731bb5fa6c863f60fd382fb /net/mac80211
parentcf147085fdda044622973a12e4e06f1c753ab677 (diff)
downloadlinux-4a199068230bd8074f2e39025a2216390ea5b829.tar.xz
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 <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211')
-rw-r--r--net/mac80211/cfg.c6
-rw-r--r--net/mac80211/main.c2
-rw-r--r--net/mac80211/util.c9
3 files changed, 9 insertions, 8 deletions
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 038c31336167..e4a370b42a93 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -739,11 +739,8 @@ static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
return 0;
mutex_lock(&local->mtx);
- mutex_lock(&local->iflist_mtx);
if (local->use_chanctx) {
- sdata = rcu_dereference_protected(
- local->monitor_sdata,
- lockdep_is_held(&local->iflist_mtx));
+ sdata = rtnl_dereference(local->monitor_sdata);
if (sdata) {
ieee80211_vif_release_channel(sdata);
ret = ieee80211_vif_use_channel(sdata, chandef,
@@ -756,7 +753,6 @@ static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
if (ret == 0)
local->monitor_chandef = *chandef;
- mutex_unlock(&local->iflist_mtx);
mutex_unlock(&local->mtx);
return ret;
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index ae408a96c407..8aa1f5b6a051 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -253,6 +253,7 @@ static void ieee80211_restart_work(struct work_struct *work)
WARN(test_bit(SCAN_HW_SCANNING, &local->scanning),
"%s called with hardware scan in progress\n", __func__);
+ flush_work(&local->radar_detected_work);
rtnl_lock();
list_for_each_entry(sdata, &local->interfaces, list)
flush_delayed_work(&sdata->dec_tailroom_needed_wk);
@@ -1187,6 +1188,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw)
cancel_work_sync(&local->reconfig_filter);
cancel_work_sync(&local->tdls_chsw_work);
flush_work(&local->sched_scan_stopped_work);
+ flush_work(&local->radar_detected_work);
ieee80211_clear_tx_pending(local);
rate_control_deinitialize(local);
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);