Date: Wed, 13 Jun 2012 13:50:07 -0700
From: "Pedersen, Thomas" <c_tpeder@qca.qualcomm.com>
To: Kalle Valo <kvalo@qca.qualcomm.com>
CC: Luciano Coelho <coelho@ti.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	<ath6kl-devel@qualcomm.com>, <linux-wireless@vger.kernel.org>,
	<victorg@ti.com>
Subject: Re: [PATCH] nl80211: specify RSSI threshold when scanning
Message-ID: <20120613205007.GB3043@pista> (sfid-20120613_225509_204417_A1F9A48C)
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On Wed, Jun 13, 2012 at 02:56:26PM +0300, Kalle Valo wrote:
> On 06/13/2012 02:37 PM, Luciano Coelho wrote:
> > On Wed, 2012-06-13 at 07:40 +0200, Johannes Berg wrote:
> >> On Tue, 2012-06-12 at 13:43 -0700, Thomas Pedersen wrote:
> >>> Support configuring an RSSI threshold in dBm (s32) when requesting
> >>> scheduled scan, below which a BSS won't be reported by the cfg80211
> >>> driver.
> >>
> >> I'm confused -- were you going to do scheduled scan only? Makes sense,
> >> but if you could maybe change the subject a bit to "specify ... in
> >> scheduled scan"?
> > 
> > It makes more sense with scheduled scans, but maybe it is also desirable
> > with normal scans to reduce the amount of scan results traffic?
> > 
> > At least if we consider the intermediate scan results that Victor has
> > been working on... We may want to report all scan results at the end,
> > but only send intermediate events if all the matches are satisfied, for
> > example.
> > 
> > Just thinking out loud a bit.
> 
> Good point.
> 
> Funnily enough I don't have any idea how ath6kl has implemented this
> feature, but in theory this feature is useful also for the current
> normal scan (when the firmware/hardware supports it) as we can avoid
> host wakeups. If there are 10 APs, but all are below the RSSI threshold,
> we will have only 1 host wakeup (scan ready event) opposed to 11 wakeups
> (10 AP found events plus 1 scan ready event).

But can the host even sleep on normal scans?

If so, maybe it makes sense to convert NL80211_ATTR_SCHED_SCAN_MATCH
into general scan matching parameters instead of having a set for each
scan type?

Thomas