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mac80211: support RX_FLAG_MACTIME_END

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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>
This commit is contained in:
Thomas Pedersen
2012-11-13 10:46:27 -08:00
committed by Johannes Berg
parent 2a91c9f781
commit f4bda337bb
23 changed files with 108 additions and 83 deletions
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29
net/mac80211/ibss.c
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@@ -543,30 +543,11 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
goto put_bss;
if (rx_status->flag & RX_FLAG_MACTIME_MPDU) {
/*
* For correct IBSS merging we need mactime; since 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)
* - equals the time this bit arrives at the receiver - we have
* to take into account the offset between the two.
*
* E.g. at 1 MBit that means mactime is 192 usec earlier
* (=24 bytes * 8 usecs/byte) than the beacon timestamp.
*/
int rate;
if (rx_status->flag & RX_FLAG_HT)
rate = 65; /* TODO: HT rates */
else
rate = local->hw.wiphy->bands[band]->
bitrates[rx_status->rate_idx].bitrate;
rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
if (ieee80211_have_rx_timestamp(rx_status)) {
/* time when timestamp field was received */
rx_timestamp =
ieee80211_calculate_rx_timestamp(local, rx_status,
len + FCS_LEN, 24);
} else {
/*
* second best option: get current TSF