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/util.c b/net/mac80211/util.c
index 4e4f585..5bad758 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2013,3 +2013,54 @@
return 2;
return 1;
}
+
+/**
+ * ieee80211_calculate_rx_timestamp - calculate timestamp in frame
+ * @local: mac80211 hw info struct
+ * @status: RX status
+ * @mpdu_len: total MPDU length (including FCS)
+ * @mpdu_offset: offset into MPDU to calculate timestamp at
+ *
+ * This function calculates the RX timestamp at the given MPDU offset, taking
+ * into account what the RX timestamp was. An offset of 0 will just normalize
+ * the timestamp to TSF at beginning of MPDU reception.
+ */
+u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
+ struct ieee80211_rx_status *status,
+ unsigned int mpdu_len,
+ unsigned int mpdu_offset)
+{
+ u64 ts = status->mactime;
+ struct rate_info ri;
+ u16 rate;
+
+ if (WARN_ON(!ieee80211_have_rx_timestamp(status)))
+ return 0;
+
+ memset(&ri, 0, sizeof(ri));
+
+ /* Fill cfg80211 rate info */
+ if (status->flag & RX_FLAG_HT) {
+ ri.mcs = status->rate_idx;
+ ri.flags |= RATE_INFO_FLAGS_MCS;
+ if (status->flag & RX_FLAG_40MHZ)
+ ri.flags |= RATE_INFO_FLAGS_40_MHZ_WIDTH;
+ if (status->flag & RX_FLAG_SHORT_GI)
+ ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
+ } else {
+ struct ieee80211_supported_band *sband;
+
+ sband = local->hw.wiphy->bands[status->band];
+ ri.legacy = sband->bitrates[status->rate_idx].bitrate;
+ }
+
+ rate = cfg80211_calculate_bitrate(&ri);
+
+ /* rewind from end of MPDU */
+ if (status->flag & RX_FLAG_MACTIME_END)
+ ts -= mpdu_len * 8 * 10 / rate;
+
+ ts += mpdu_offset * 8 * 10 / rate;
+
+ return ts;
+}