Subject: Re: [PATCH 01/19] orinoco: Add ESSID specific scanning for Agere fw
From: Dan Williams <dcbw@redhat.com>
To: Dave <kilroyd@googlemail.com>
Cc: Pavel Roskin <proski@gnu.org>, linux-wireless@vger.kernel.org,
	orinoco-devel@lists.sourceforge.net,
	Jean Tourrilhes <jt@hpl.hp.com>
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Date: Wed, 06 Aug 2008 22:48:20 -0400
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On Wed, 2008-08-06 at 22:08 +0100, Dave wrote:
> Dan Williams wrote:
> > On Wed, 2008-08-06 at 20:29 +0100, Dave wrote:
> >> Dan Williams wrote:
> >>> On Tue, 2008-08-05 at 18:48 -0400, Pavel Roskin wrote:
> >>>> The userspace is welcome to keep a pool of all APs found by any scans,
> >>>> but I don't think drivers should do it.
> >>> Drivers need to keep a reasonably complete list of APs internally for
> >>> association anyway.  You don't want to have to do a full scan just to
> >>> associate if you have results from 10 seconds ago that are still valid.
> 
> >> This is not an issue for orinoco cards, as the firmware selects
> >> the AP to use independently of any driver scanning. The requirement to
> >> use ap_scan=2 means that wpa_supplicant doesn't need to look at the scan
> >> results either (except maybe to verify the configuration matches).
> 
> > Well, since the driver supports SSID scanning, we can use ap_scan=1
> > anyway.  ap_scan=2 is actually pretty evil since it depends on WEXT
> > ordering and whatnot.
> 
> ap_scan=1 requires the use of SIOCSIWWAP (to set desired BSSID), which
> the Agere firmware doesn't support. The firmware only supports setting a
> desired SSID (via SIOCSIWESSID), so Agere based orinoco is stuck with
> ap_scan=2 :(
> 
> Symbol and Intersil don't have this problem.

In practice that shouldn't be a problem because drivers (at least
ipw2200 does this) usually roam BSSIDs anyway.  Technically a bug I
think.  But honestly, the driver needs to work with ap_scan=1 and I
don't see why it couldn't.

Dan