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authorJavier Cardona <javier@cozybit.com>2012-04-12 14:32:22 -0700
committerJohn W. Linville <linville@tuxdriver.com>2012-04-16 14:19:29 -0400
commita802a6eba13282ddd5718f8db9d476e42e84e2ba (patch)
tree3d33cd0424d8c227260a748f35f2d5a4ff43b72c /net/mac80211/mesh_sync.c
parentb6ba82c893c48cfe48a98ee3dc50011832e764bd (diff)
downloadlinux-stericsson-a802a6eba13282ddd5718f8db9d476e42e84e2ba.tar.gz
mac80211: Choose a new toffset setpoint if a big tsf jump is detected.
Signed-off-by: Javier Cardona <javier@cozybit.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/mesh_sync.c')
-rw-r--r--net/mac80211/mesh_sync.c26
1 files changed, 20 insertions, 6 deletions
diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c
index f78b0139856f..22a5f1e66996 100644
--- a/net/mac80211/mesh_sync.c
+++ b/net/mac80211/mesh_sync.c
@@ -22,7 +22,14 @@
/* This is not in the standard. It represents a tolerable tbtt drift below
* which we do no TSF adjustment.
*/
-#define TBTT_MINIMUM_ADJUSTMENT 10
+#define TOFFSET_MINIMUM_ADJUSTMENT 10
+
+/* This is not in the standard. It represents the maximum Toffset jump above
+ * which we'll invalidate the Toffset setpoint and choose a new setpoint. This
+ * could be, for instance, in case a neighbor is restarted and its TSF counter
+ * reset.
+ * */
+#define TOFFSET_MAXIMUM_ADJUSTMENT 30000 /* 30 ms */
struct sync_method {
u8 method;
@@ -156,15 +163,22 @@ static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
if (test_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN)) {
s64 t_clockdrift = sta->t_offset_setpoint
- sta->t_offset;
-
- msync_dbg("STA %pM : sta->t_offset=%lld,"
- " sta->t_offset_setpoint=%lld,"
- " t_clockdrift=%lld",
+ msync_dbg("STA %pM : sta->t_offset=%lld, sta->t_offset_setpoint=%lld, t_clockdrift=%lld",
sta->sta.addr,
(long long) sta->t_offset,
(long long)
sta->t_offset_setpoint,
(long long) t_clockdrift);
+
+ if (t_clockdrift > TOFFSET_MAXIMUM_ADJUSTMENT ||
+ t_clockdrift < -TOFFSET_MAXIMUM_ADJUSTMENT) {
+ msync_dbg("STA %pM : t_clockdrift=%lld too large, setpoint reset",
+ sta->sta.addr,
+ (long long) t_clockdrift);
+ clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
+ goto no_sync;
+ }
+
rcu_read_unlock();
spin_lock_bh(&ifmsh->sync_offset_lock);
@@ -200,7 +214,7 @@ static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
spin_lock_bh(&ifmsh->sync_offset_lock);
if (ifmsh->sync_offset_clockdrift_max >
- TBTT_MINIMUM_ADJUSTMENT) {
+ TOFFSET_MINIMUM_ADJUSTMENT) {
/* Since ajusting the tsf here would
* require a possibly blocking call
* to the driver tsf setter, we punt