mac80211: Remove invalid flag operations in mesh TSF synchronization

mesh_sync_offset_adjust_tbtt() implements Extensible synchronization
framework ([1] 13.13.2 Extensible synchronization framework). It shall
not operate the flag "TBTT Adjusting subfield" ([1] 8.4.2.100.8 Mesh
Capability), since it is used only for MBCA ([1] 13.13.4 Mesh beacon
collision avoidance, see 13.13.4.4.3 TBTT scanning and adjustment
procedures for detail). So this patch remove the flag operations.

[1] IEEE Std 802.11 2012

Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
[remove adjusting_tbtt entirely, since it's now unused]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/ieee80211_i.h

@@ -689,7 +689,6 @@ struct ieee80211_if_mesh {
 	const struct ieee80211_mesh_sync_ops *sync_ops;
 	s64 sync_offset_clockdrift_max;
 	spinlock_t sync_offset_lock;
-	bool adjusting_tbtt;
 	/* mesh power save */
 	enum nl80211_mesh_power_mode nonpeer_pm;
 	int ps_peers_light_sleep;

net/mac80211/mesh.c

@@ -279,8 +279,6 @@ int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
 	/* Mesh PS mode. See IEEE802.11-2012 8.4.2.100.8 */
 	*pos |= ifmsh->ps_peers_deep_sleep ?
 			IEEE80211_MESHCONF_CAPAB_POWER_SAVE_LEVEL : 0x00;
-	*pos++ |= ifmsh->adjusting_tbtt ?
-			IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING : 0x00;
 	*pos++ = 0x00;
 
 	return 0;
@@ -850,7 +848,6 @@ int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
 	ifmsh->mesh_cc_id = 0;	/* Disabled */
 	/* register sync ops from extensible synchronization framework */
 	ifmsh->sync_ops = ieee80211_mesh_sync_ops_get(ifmsh->mesh_sp_id);
-	ifmsh->adjusting_tbtt = false;
 	ifmsh->sync_offset_clockdrift_max = 0;
 	set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
 	ieee80211_mesh_root_setup(ifmsh);

net/mac80211/mesh_sync.c

@@ -123,7 +123,6 @@ static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 	 */
 
 	if (elems->mesh_config && mesh_peer_tbtt_adjusting(elems)) {
-		clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
 		msync_dbg(sdata, "STA %pM : is adjusting TBTT\n",
 			  sta->sta.addr);
 		goto no_sync;
@@ -172,11 +171,9 @@ 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);
 	WARN_ON(!rcu_read_lock_held());
-	cap = beacon->meshconf->meshconf_cap;
 
 	spin_lock_bh(&ifmsh->sync_offset_lock);
 
@@ -190,21 +187,13 @@ static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata,
 			  "TBTT : kicking off TBTT adjustment with clockdrift_max=%lld\n",
 			  ifmsh->sync_offset_clockdrift_max);
 		set_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags);
-
-		ifmsh->adjusting_tbtt = true;
 	} else {
 		msync_dbg(sdata,
 			  "TBTT : max clockdrift=%lld; too small to adjust\n",
 			  (long long)ifmsh->sync_offset_clockdrift_max);
 		ifmsh->sync_offset_clockdrift_max = 0;
-
-		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[] = {