From f4bda337bbb6e245e2a07f344990adeb6a70ff35 Mon Sep 17 00:00:00 2001 From: Thomas Pedersen Date: Tue, 13 Nov 2012 10:46:27 -0800 Subject: 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 [fix docs, atheros drivers] Signed-off-by: Johannes Berg --- net/mac80211/mesh_sync.c | 44 +++++++------------------------------------- 1 file changed, 7 insertions(+), 37 deletions(-) (limited to 'net/mac80211/mesh_sync.c') diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c index 407c8705e10d..9c6ea9cfe1b3 100644 --- a/net/mac80211/mesh_sync.c +++ b/net/mac80211/mesh_sync.c @@ -116,43 +116,13 @@ static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata, 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); -- cgit v1.2.1