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| author | Javier Cardona <javier@cozybit.com> | 2012-04-12 14:32:22 -0700 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2012-04-16 14:19:29 -0400 |
| commit | a802a6eba13282ddd5718f8db9d476e42e84e2ba (patch) | |
| tree | 3d33cd0424d8c227260a748f35f2d5a4ff43b72c /net | |
| parent | b6ba82c893c48cfe48a98ee3dc50011832e764bd (diff) | |
| download | blackbird-obmc-linux-a802a6eba13282ddd5718f8db9d476e42e84e2ba.tar.gz blackbird-obmc-linux-a802a6eba13282ddd5718f8db9d476e42e84e2ba.zip | |
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')
| -rw-r--r-- | net/mac80211/mesh_sync.c | 26 |
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 |
