Message-ID: <1ba2fa240802041201o11107a8o14b969bacdf5345@mail.gmail.com> (sfid-20080204_200116_589977_5FD2BA17)
Date: Mon, 4 Feb 2008 22:01:09 +0200
From: "Tomas Winkler" <tomasw@gmail.com>
To: "Kalle Valo" <kalle.valo@nokia.com>
Subject: Re: cfg80211 API changes
Cc: "Sam Leffler" <sam@errno.com>,
	"Johannes Berg" <johannes@sipsolutions.net>,
	linux-wireless@vger.kernel.org,
	"Ron Rindjunsky" <ron.rindjunsky@intel.com>
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On Feb 4, 2008 8:20 PM, Kalle Valo <kalle.valo@nokia.com> wrote:
> Sam Leffler <sam@errno.com> writes:
>
> >>> I see.  Rate scale algorithm only tels FW from what rate to start
> >>> transmission. FW is responsible to do downscaling.  Which is quite
> >>> reasonable as retransmission is real time process. Instead of
> >>> retransmitting on the same rate FW downscales. T X response provides
> >>> to the rate scaling algorithm the successful rate.
> >>
> >> I just want to point out this is an important feature when the bus is
> >> very slow, for example SPI bus in embedded devices. Retransfering
> >> frames through SPI for every rate restransmit would make such a device
> >> extremely slow.
> >
> > I don't know of a part that does repeated DMA to implement retransmit;
> > do you have an example?
>
> Asking me? No, I have never heard of such a device.
>
Actually what is probably happening with some devices, I'm not sure
though, they retries in FW/HW but do not downscale.

Tomas

> Kalle Valo
>