[PATCH] mac80211: remove unnecessary iflist_mtx locking

[PATCH] mac80211: remove unnecessary iflist_mtx locking

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

The radar detection code changed a few times, and due to
the changes some iflist_mtx locking stayed in that isn't
actually necessary - remove it.

One version of the code needed it because an AP interface's
VLAN list was changed to use this, but then we moved the
list handling outside of the chanctx handling and thus the
locking was no longer needed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/cfg.c   | 2 --
 net/mac80211/iface.c | 2 --
 2 files changed, 4 deletions(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index ac18528..bfe54da 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2903,10 +2903,8 @@ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 	sdata->needed_rx_chains = local->rx_chains;
 	sdata->radar_required = true;
 
-	mutex_lock(&local->iflist_mtx);
 	err = ieee80211_vif_use_channel(sdata, chandef,
 					IEEE80211_CHANCTX_SHARED);
-	mutex_unlock(&local->iflist_mtx);
 	if (err)
 		return err;
 
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 3d2168c..0c0be90 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -826,9 +826,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 	if (sdata->wdev.cac_started) {
 		chandef = sdata->vif.bss_conf.chandef;
 		WARN_ON(local->suspended);
-		mutex_lock(&local->iflist_mtx);
 		ieee80211_vif_release_channel(sdata);
-		mutex_unlock(&local->iflist_mtx);
 		cfg80211_cac_event(sdata->dev, &chandef,
 				   NL80211_RADAR_CAC_ABORTED,
 				   GFP_KERNEL);
-- 
1.8.5.1

Re: [PATCH] mac80211: remove unnecessary iflist_mtx locking

[Johannes Berg]

On Wed, 2013-12-18 at 20:01 +0100, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com>
> 
> The radar detection code changed a few times, and due to
> the changes some iflist_mtx locking stayed in that isn't
> actually necessary - remove it.
> 
> One version of the code needed it because an AP interface's
> VLAN list was changed to use this, but then we moved the
> list handling outside of the chanctx handling and thus the
> locking was no longer needed.

Applied.

johannes