Commit ec14bcd2 authored by Javier Cardona's avatar Javier Cardona Committed by John W. Linville
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mac80211: Take into account TSF adjustment latency in Toffset setpoint



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: default avatarShinichi Hotori <hotorinn@gmail.com>
Signed-off-by: default avatarYu Niiro <yu.niiro@gmail.com>
Signed-off-by: default avatarJavier Cardona <javier@cozybit.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent a802a6eb
......@@ -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 {
......
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