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>
This commit is contained in:
Javier Cardona 2012-04-12 14:32:22 -07:00 committed by John W. Linville
parent b6ba82c893
commit a802a6eba1
1 changed files with 20 additions and 6 deletions

View File

@ -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