From e14296cabac60806606b4ebc1a83ee4697876346 Mon Sep 17 00:00:00 2001 From: Bruno Randolf Date: Wed, 5 Mar 2008 18:36:05 +0900 Subject: [PATCH] ath5k: add notes about rx timestamp add comments about the fact that we don't know when exactly the atheros hardware takes the RX timestamp. drivers/net/wireless/ath5k/base.c: Changes-licensed-under: 3-Clause-BSD Signed-off-by: Bruno Randolf Signed-off-by: John W. Linville --- drivers/net/wireless/ath5k/base.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c index 73e7e61..5eacc7c 100644 --- a/drivers/net/wireless/ath5k/base.c +++ b/drivers/net/wireless/ath5k/base.c @@ -1844,6 +1844,17 @@ accept: * 15bit only. that means TSF extension has to be done within * 32768usec (about 32ms). it might be necessary to move this to * the interrupt handler, like it is done in madwifi. + * + * Unfortunately we don't know when the hardware takes the rx + * timestamp (beginning of phy frame, data frame, end of rx?). + * The only thing we know is that it is hardware specific... + * On AR5213 it seems the rx timestamp is at the end of the + * frame, but i'm not sure. + * + * NOTE: mac80211 defines mactime at the beginning of the first + * data symbol. Since we don't have any time references it's + * impossible to comply to that. This affects IBSS merge only + * right now, so it's not too bad... */ rxs.mactime = ath5k_extend_tsf(sc->ah, rs.rs_tstamp); rxs.flag |= RX_FLAG_TSFT; -- 2.7.4