mac80211: add RX_FLAG_MACTIME_PLCP_START

The timestamp given by iwlwifi is at the beginning of the
frame over the air, at (or during) the SYNC field. Allow
such timestamps to be given to mac80211, at least (for now)
for frames with non-HT/VHT preambles.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 566df20dc95757c9f2c13cbe2b467d3d2e1d18a0..31337f81ec03860cfbc54ee0c47fb1088f32975b 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1010,6 +1010,8 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
  * @RX_FLAG_MACTIME_END: The timestamp passed in the RX status (@mactime
  *     field) is valid and contains the time the last symbol of the MPDU
  *     (including FCS) was received.
+ * @RX_FLAG_MACTIME_PLCP_START: The timestamp passed in the RX status (@mactime
+ *     field) is valid and contains the time the SYNC preamble was received.
  * @RX_FLAG_SHORTPRE: Short preamble was used for this frame
  * @RX_FLAG_HT: HT MCS was used and rate_idx is MCS index
  * @RX_FLAG_VHT: VHT MCS was used and rate_index is MCS index
@@ -1058,6 +1060,7 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
 enum mac80211_rx_flags {
        RX_FLAG_MMIC_ERROR              = BIT(0),
        RX_FLAG_DECRYPTED               = BIT(1),
+       RX_FLAG_MACTIME_PLCP_START      = BIT(2),
        RX_FLAG_MMIC_STRIPPED           = BIT(3),
        RX_FLAG_IV_STRIPPED             = BIT(4),
        RX_FLAG_FAILED_FCS_CRC          = BIT(5),

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 9934447a8b9a4ee58284e79cce867a7eadd2a6ac..a29f61dc9c0608ed03c7b64755beb644ed066313 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1466,7 +1466,13 @@ ieee80211_have_rx_timestamp(struct ieee80211_rx_status *status)
 {
        WARN_ON_ONCE(status->flag & RX_FLAG_MACTIME_START &&
                     status->flag & RX_FLAG_MACTIME_END);
-       return status->flag & (RX_FLAG_MACTIME_START | RX_FLAG_MACTIME_END);
+       if (status->flag & (RX_FLAG_MACTIME_START | RX_FLAG_MACTIME_END))
+               return true;
+       /* can't handle HT/VHT preamble yet */
+       if (status->flag & RX_FLAG_MACTIME_PLCP_START &&
+           !(status->flag & (RX_FLAG_HT | RX_FLAG_VHT)))
+               return true;
+       return false;
 }
 
 u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 7d0479e316744bed60ac88964c5654146c6e947f..fb90d9c5df59ea426e818973b1e1ebc843f963d1 100644 (file)
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -4,7 +4,7 @@
  * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
  * Copyright 2007      Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
- * Copyright (C) 2015  Intel Deutschland GmbH
+ * Copyright (C) 2015-2016     Intel Deutschland GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -2671,6 +2671,18 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
                sband = local->hw.wiphy->bands[status->band];
                bitrate = sband->bitrates[status->rate_idx].bitrate;
                ri.legacy = DIV_ROUND_UP(bitrate, (1 << shift));
+
+               if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
+                       /* TODO: handle HT/VHT preambles */
+                       if (status->band == IEEE80211_BAND_5GHZ) {
+                               ts += 20 << shift;
+                               mpdu_offset += 2;
+                       } else if (status->flag & RX_FLAG_SHORTPRE) {
+                               ts += 96;
+                       } else {
+                               ts += 192;
+                       }
+               }
        }
 
        rate = cfg80211_calculate_bitrate(&ri);