mac80211: support RX_FLAG_MACTIME_END
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>
diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c
index 407c870..9c6ea9c 100644
--- a/net/mac80211/mesh_sync.c
+++ b/net/mac80211/mesh_sync.c
@@ -116,43 +116,13 @@
goto no_sync;
}
- if (rx_status->flag & RX_FLAG_MACTIME_MPDU && rx_status->mactime) {
- /*
- * The mactime is defined as the time the first data symbol
- * of the frame hits the PHY, and the timestamp of the beacon
- * is defined as "the time that the data symbol containing the
- * first bit of the timestamp is transmitted to the PHY plus
- * the transmitting STA's delays through its local PHY from the
- * MAC-PHY interface to its interface with the WM" (802.11
- * 11.1.2)
- *
- * T_r, in 13.13.2.2.2, is just defined as "the frame reception
- * time" but we unless we interpret that time to be the same
- * time of the beacon timestamp, the offset calculation will be
- * off. Below we adjust t_r to be "the time at which the first
- * symbol of the timestamp element in the beacon is received".
- * This correction depends on the rate.
- *
- * Based on similar code in ibss.c
- */
- int rate;
-
- if (rx_status->flag & RX_FLAG_HT) {
- /* TODO:
- * In principle there could be HT-beacons (Dual Beacon
- * HT Operation options), but for now ignore them and
- * just use the primary (i.e. non-HT) beacons for
- * synchronization.
- * */
- goto no_sync;
- } else
- rate = local->hw.wiphy->bands[rx_status->band]->
- bitrates[rx_status->rate_idx].bitrate;
-
- /* 24 bytes of header * 8 bits/byte *
- * 10*(100 Kbps)/Mbps / rate (100 Kbps)*/
- t_r = rx_status->mactime + (24 * 8 * 10 / rate);
- }
+ if (ieee80211_have_rx_timestamp(rx_status))
+ /* time when timestamp field was received */
+ t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
+ 24 + 12 +
+ elems->total_len +
+ FCS_LEN,
+ 24);
/* Timing offset calculation (see 13.13.2.2.2) */
t_t = le64_to_cpu(mgmt->u.beacon.timestamp);