From 8c358bcd097fa1f63e57fb82525ba52f4a537bfa Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 22 May 2012 22:13:05 +0200 Subject: mac80211: add time synchronisation with BSS for assoc Some drivers (iwlegacy, iwlwifi and rt2x00) today use the bss_conf.last_tsf value. By itself though that value is completely worthless since it may be ancient. What really is needed is synchronisation between some device time and the TSF. To clarify this, rename bss_conf.last_tsf to sync_tsf and add sync_device_ts which is obtained from rx_status which gets a new field device_timestamp for this purpose. This is intentionally not using the mactime field since that is used for other things and in IBSS is expected to sync with the IBSS's TSF which isn't necessarily true for the device timestamp. Also, since we have the information and it's useful even before the connection has been established, give all the timing details to the driver before authenticating. Reviewed-by: Emmanuel Grumbach Signed-off-by: Johannes Berg --- include/net/mac80211.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include/net/mac80211.h') diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 7300cb51dd5f..bb86aa6f98dd 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -233,8 +233,10 @@ enum ieee80211_rssi_event { * valid in station mode only while @assoc is true and if also * requested by %IEEE80211_HW_NEED_DTIM_PERIOD (cf. also hw conf * @ps_dtim_period) - * @last_tsf: last beacon's/probe response's TSF timestamp (could be old + * @sync_tsf: last beacon's/probe response's TSF timestamp (could be old * as it may have been received during scanning long ago) + * @sync_device_ts: the device timestamp corresponding to the sync_tsf, + * the driver/device can use this to calculate synchronisation * @beacon_int: beacon interval * @assoc_capability: capabilities taken from assoc resp * @basic_rates: bitmap of basic rates, each bit stands for an @@ -281,7 +283,8 @@ struct ieee80211_bss_conf { u8 dtim_period; u16 beacon_int; u16 assoc_capability; - u64 last_tsf; + u64 sync_tsf; + u32 sync_device_ts; u32 basic_rates; int mcast_rate[IEEE80211_NUM_BANDS]; u16 ht_operation_mode; @@ -696,6 +699,8 @@ enum mac80211_rx_flags { * * @mactime: value in microseconds of the 64-bit Time Synchronization Function * (TSF) timer when the first data symbol (MPDU) arrived at the hardware. + * @device_timestamp: arbitrary timestamp for the device, mac80211 doesn't use + * it but can store it and pass it back to the driver for synchronisation * @band: the active band when this frame was received * @freq: frequency the radio was tuned to when receiving this frame, in MHz * @signal: signal strength when receiving this frame, either in dBm, in dB or @@ -709,6 +714,7 @@ enum mac80211_rx_flags { */ struct ieee80211_rx_status { u64 mactime; + u32 device_timestamp; u16 flag; u16 freq; u8 rate_idx; -- cgit v1.2.3