Subject: Re: Power saving on mac80211
From: Johannes Berg <johannes@sipsolutions.net>
To: Kalle Valo <kalle.valo@nokia.com>
Cc: "Luis R. Rodriguez" <mcgrof@gmail.com>,
	linux-wireless <linux-wireless@vger.kernel.org>,
	Zhu Yi <yi.zhu@intel.com>
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References: <43e72e890810171810t1c65642g998db601cfe2a390@mail.gmail.com>
	 <87bpxh6t1n.fsf@nokia.com> <87y70l59p4.fsf@nokia.com>
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	 <1224434885.6324.49.camel@johannes.berg>  <87myh0a1zd.fsf@nokia.com>
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Date: Sun, 19 Oct 2008 20:49:36 +0200
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On Sun, 2008-10-19 at 21:12 +0300, Kalle Valo wrote:

> > It seems to be a firmware feature, first beacon from the BSS the
> > firmware computes the checksum, and if it changes it lets the beacon go
> > through and re-computes the checksum, so you see all beacon changes.
>=20
> So the driver doesn't have to compute any checksums itself? That makes
> things easy then.

=46rom what I'm reading in the firmware docs, no.

> > Maybe it excludes the TIM.
>=20
> It should. Otherwise beacon filtering in a crowded network with
> clients in PSM would be next to useless. And I didn't see any major
> increase in power consumption at Maemo Summit :)

Indeed :)

> > I think we want this for when the QoS parameters or something else
> > changes.
>=20
> Yeah. Just out of curiosity, are there any other parameters which
> mac80211 needs to follow? Short preamble? Short slot time? Anything
> else?

I think that's about it. Maybe something else in IBSS, if that works
there at all.

johannes

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