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Date:      Tue, 13 Jan 2004 09:40:23 -0800
From:      Sam Leffler <sam@errno.com>
To:        David Gilbert <dgilbert@dclg.ca>
Cc:        freebsd-mobile@freebsd.org
Subject:   Re: ATH driver doesn't associate with turbo.
Message-ID:  <200401130940.23993.sam@errno.com>
In-Reply-To: <16387.58499.587197.601294@canoe.dclg.ca>
References:  <16248.58260.560180.809655@canoe.dclg.ca> <200401122149.06369.sam@errno.com> <16387.58499.587197.601294@canoe.dclg.ca>

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On Tuesday 13 January 2004 04:28 am, David Gilbert wrote:
> >>>>> "Sam" == Sam Leffler <sam@errno.com> writes:
>
> Sam> On Monday 29 September 2003 06:59 pm, David Gilbert wrote:
> >> If I put my access point in turbo mode, the ath driver won't
> >> associate with it.  Additionally, the documentation for my card
> >> says that it should support upto 108Mbps in turbo mode, but the ath
> >> driver doesn't detect this.
>
> Sam> What do you base this on?  The turbo rates happen to be printed
> Sam> as 1/2 the actual speed.because the actual rate is done by
> Sam> overclocking and not by negotiating a different xmit rate.  I've
> Sam> thought about artificially printing them as 2x values so people
> Sam> stop complaining. :)
>
> Fair enough.  If this is the case, then things are correct.
>
> Sam> As to not being able to associate in turbo mode; you don't show
> Sam> how you configured the interface.  Atheros-based AP's that
> Sam> support "SuperG" use a proprietary protocol handshake to
> Sam> negotiate use of turbo mode.  The current driver doesn't support
> Sam> this though I recently got the info I need to add it.  For "old
> Sam> turbo" mode you have to manually enable it with ifconfig before
> Sam> the 802.11 layer will assoociate with a turbo AP.  I've
> Sam> considered changing this but adding turbo mode channels to the
> Sam> scan list would more often than not just lengthen the scanning
> Sam> process and rarely be used.
>
> The access point is an A-only unit made by Netgear.  It advertises
> turbo modes only upto 72 megabit in it's documentation.
>

This is a 5210-based product.  Turbo mode, if I recall, didn't work all that 
great.  Just fyi.

> Concerning your 'rarely used' comment, is it that access points based
> on Athros are rare or that turbo mode itself is not that useful?
>

Turbo mode is an Atheros-proprietary feature.  Until we have the 
auto-negotiation handshake in place in FreeBSD you must manually configure it 
on both the AP and client and when you do that you cannot fallback to 
non-turbo operation (in 11a).  This makes it a nuisance to use and so I 
believe it will be "rarely used".

> Maybe it would be sufficient to have a mode 11a-turbo in addition to
> mode 11a that is not part of the automatic scan.

Turbo was done a modified bit because it actually can be used in both 11a and 
11g operation.  I need to fix the 802.11 support to handle it better.  But 
that won't happen for a while unless someone else does it.

	Sam



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