Subject: Re: [PATCH 1/3] mac80211: better definition of mactime
From: Johannes Berg <johannes@sipsolutions.net>
To: Bruno Randolf <bruno@thinktube.com>
Cc: ath5k-devel@lists.ath5k.org, mcgrof@gmail.com, jirislaby@gmail.com,
	mickflemm@gmail.com, linux-wireless@vger.kernel.org,
	linville@tuxdriver.com, flamingice@sourmilk.net, jbenc@suse.cz
In-Reply-To: <20080215070116.32461.80795.stgit@one>
References: <20080215070116.32461.80795.stgit@one>
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Date: Fri, 15 Feb 2008 13:52:19 +0100
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On Fri, 2008-02-15 at 16:01 +0900, Bruno Randolf wrote:
> define mactime as the time when the first data symbol arrived at the HW. =
the
> old definition was questionable because 802.11 defines timestamp only for
> beacon and probe response frames, and there it means the timestamp field.
>=20
> a stricter definition of mactime is necessary for correct merging of IBSS=
.
>=20
> note that it is up to the driver to convert whatever its hardware returns=
 to
> this definition. unfortunately we don't know for example when atheros har=
dware
> takes its rx timestamp exactly :(
>=20
> Signed-off-by: Bruno Randolf <bruno@thinktube.com>

Acked-by: Johannes Berg <johannes@sipsolutions.net>

> ---
>=20
>  include/net/mac80211.h |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>=20
>=20
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index 460da54..1b807f4 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -295,7 +295,8 @@ enum mac80211_rx_flags {
>   * The low-level driver should provide this information (the subset
>   * supported by hardware) to the 802.11 code with each received
>   * frame.
> - * @mactime: MAC timestamp as defined by 802.11
> + * @mactime: value in microseconds of the 64-bit Time Synchronization Fu=
nction
> + * 	(TSF) timer when the first data symbol (MPDU) arrived at the hardwar=
e.
>   * @band: the active band when this frame was received
>   * @freq: frequency the radio was tuned to when receiving this frame, in=
 MHz
>   * @ssi: signal strength when receiving this frame
>=20
>=20

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