These functions drifts TSF timers, not TBTT.
Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
mesh_sync_offset_adjust_tbtt() implements Extensible synchronization
framework ([1] 13.13.2 Extensible synchronization framework). It shall
not operate the flag "TBTT Adjusting subfield" ([1] 8.4.2.100.8 Mesh
Capability), since it is used only for MBCA ([1] 13.13.4 Mesh beacon
collision avoidance, see 13.13.4.4.3 TBTT scanning and adjustment
procedures for detail). So this patch remove the flag operations.
[1] IEEE Std 802.11 2012
Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
[remove adjusting_tbtt entirely, since it's now unused]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The old value was 30ms, which means mesh sync will treat
any value below as merely TSF drift. This isn't really
reasonable (typical drift is < 10us/s) since people
probably want to adjust TSF in smaller increments (for ie.
beacon collision avoidance) without mesh sync fighting
back.
Change max drift adjustment to 0.8ms, so manual TSF
adjustments can be made in 1ms increments, with some
margin.
Signed-off-by: Thomas Pedersen <twp@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This allows the mesh sync (and debugfs) code to make incremental
TSF adjustments, avoiding any uncertainty introduced by delay in
programming absolute TSF.
Signed-off-by: Thomas Pedersen <twp@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There are now a fairly large number of mesh fields that really
aren't needed in any other modes; move those into their own
structure and allocate them separately.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
These BUG_ON statements should never trigger, but in the unlikely
event that somebody does manage don't stop everything but simply
exit the code path with an error.
Leave the one BUG_ON where changing it would result in a NULL
pointer dereference.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This regression was introduced in "mac80211: cache mesh
beacon".
mesh_sync_offset_adjust_tbtt() was assuming that the
beacon would be rebuilt in every single pre-tbtt
interrupt, but now the beacon update happens on the
workqueue, and it must be ready for immediate delivery to
the driver.
Save a pointer to the meshconf IE in the beacon_data (this
works because both the IE pointer and beacon buffer are
protected by the same rcu_{dereference,assign_pointer}())
for quick updates during pre-tbtt. This is faster and a
little prettier than iterating over the elements to find
the meshconf IE every time.
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The local TSF timer is used to compute the timing offset between
mesh peers on beacon reception. However, asking the device for
the TSF is not very accurate, so we prefer to use rx->mactime
if available. In the latter case, calling drv_get_tsf() just
adds more delay into the RX path, so skip it if we can.
Signed-off-by: Bob Copeland <bob@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There's various code with strange indentation,
questionable loop and locking constructs, etc.
The bigger change is moving the "sdata" argument
to the first argument of all functions, like all
other mac80211 functions that have one.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Currently the mesh sync code checks, whether peers indicate TBTT adjustment,
but it never sets the corresponding flag itself.
By setting ifmsh->tbtt_adjusting to true, it will set the corresponding field
in the mesh configuration IE of own beacons.
This indication will be set in the current beacon. The TBTT adjustment will be
performed afterwards, affecting the next beacon. Thus, the first beacon with
stable TBTT will not indicate adjustment anymore and peers will continue
tracking the new offset.
Signed-off-by: Marco Porsch <marco.porsch@etit.tu-chemnitz.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Allow drivers to indicate their mactime is at RX completion and adjust
for this in mac80211. Also rename the existing RX_FLAG_MACTIME_MPDU to
RX_FLAG_MACTIME_START to clarify its intent. Based on similar code by
Johannes Berg.
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
[fix docs, atheros drivers]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There's no vendor-specific mesh sync implemented
and there don't need to be dummy handlers that
only print messages, so remove that code. While
at it, also constify the mesh sync ops.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The call to drv_get/set_tsf() was put on the workqueue to perform tsf
adjustments since that function might sleep. However it ended up inside
a spinlock, whose critical section must be atomic. Do tsf adjustment
outside the spinlock instead, and get rid of a warning.
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
There are a few things that make the logging and
debugging in mac80211 less useful than it should
be right now:
* a lot of messages should be pr_info, not pr_debug
* wholesale use of pr_debug makes it require *both*
Kconfig and dynamic configuration
* there are still a lot of ifdefs
* the style is very inconsistent, sometimes the
sdata->name is printed in front
Clean up everything, introducing new macros and
separating out the station MLME debugging into
a new Kconfig symbol.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Standardize the debugging to be able to use dynamic_debug.
Coalesce formats, align arguments.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The original patch defined the correction margin but did not apply it.
Signed-off-by: Shinichi Hotori <hotorinn@gmail.com>
Signed-off-by: Yu Niiro <yu.niiro@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 <hotorinn@gmail.com>
Signed-off-by: Yu Niiro <yu.niiro@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch adds MBSS extensible synchronization framework (Sec.
13.13.2 of IEEE Std. 802.11-2012).
The framework is implemented via an ops table which defines the
following functions:
rx_bcn_presp() - this is called every time a mesh beacon is
received.
adjust_tbtt() - this is called immediately before a beacon is about
to be transmitted.
The default neighbor offset synchronization defined in the standard is
implemented. We also provide template functions for vendor specific
methods.
When neighbor offset synchronization is active (which is the default)
mesh neighbors in the same MBSS will track timing offsets to each other
and compensate clock drift.
In our tests we observed that this mesh synchronization implementation
successfully corrected drifts between stations of ~2PPM while
introducing a jitter of ~20us.
It is also possible to test this framework on mac80211_hwsim simulated
phys to see how it behaves under different topologies, over poor links,
etc.
Signed-off-by: Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
Signed-off-by: Pavel Zubarev <pavel.zubarev@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Masashi Honma