When testing mesh synchronization we observed a global TSF slowdown that was dependent on the number of synchronized mesh stations. This seems to be caused by the TSF adjustment (read/write) latency.
Adding a small margin to the Toffset setpoint solved the problem. Signed-off-by: Shinichi Hotori <[email protected]> Signed-off-by: Yu Niiro <[email protected]> Signed-off-by: Javier Cardona <[email protected]> --- net/mac80211/mesh_sync.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c index 22a5f1e..ff60d6b 100644 --- a/net/mac80211/mesh_sync.c +++ b/net/mac80211/mesh_sync.c @@ -24,11 +24,17 @@ */ #define TOFFSET_MINIMUM_ADJUSTMENT 10 +/* This is not in the standard. It is a margin added to the + * Toffset setpoint to mitigate TSF overcorrection + * introduced by TSF adjustment latency. + */ +#define TOFFSET_SET_MARGIN 20 + /* 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 { -- 1.7.5.4 _______________________________________________ Devel mailing list [email protected] http://lists.open80211s.org/cgi-bin/mailman/listinfo/devel
