mac80211: update adjusting TBTT bit in beacon

This regression was introduced in "mac80211: cache mesh
beacon".

mesh_sync_offset_adjust_tbtt()  was assuming that the
beacon would be rebuilt in every single pre-tbtt
interrupt, but now the beacon update happens on the
workqueue, and it must be ready for immediate delivery to
the driver.

Save a pointer to the meshconf IE in the beacon_data (this
works because both the IE pointer and beacon buffer are
protected by the same rcu_{dereference,assign_pointer}())
for quick updates during pre-tbtt. This is faster and a
little prettier than iterating over the elements to find
the meshconf IE every time.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c
index d1cf2d553499..2bc5dc25d5ad 100644
--- a/net/mac80211/mesh_sync.c
+++ b/net/mac80211/mesh_sync.c
@@ -164,12 +164,15 @@ no_sync:
 	rcu_read_unlock();
 }
 
-static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
+static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata,
+					 struct beacon_data *beacon)
 {
 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+	u8 cap;
 
 	WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);
 	BUG_ON(!rcu_read_lock_held());
+	cap = beacon->meshconf->meshconf_cap;
 
 	spin_lock_bh(&ifmsh->sync_offset_lock);
 
@@ -194,6 +197,10 @@ static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
 		ifmsh->adjusting_tbtt = false;
 	}
 	spin_unlock_bh(&ifmsh->sync_offset_lock);
+
+	beacon->meshconf->meshconf_cap = ifmsh->adjusting_tbtt ?
+			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING | cap :
+			~IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING & cap;
 }
 
 static const struct sync_method sync_methods[] = {