2007-11-23 16:31:40

by Nicolas Ferre

[permalink] [raw]
Subject: Wifi chips on SDIO interface

Hi,

To follow up on a recent thread on the arm-linux mailing list, I would
like to have your your feedback about SDIO wifi cards you are using with
the brand new SDIO stack.

I look at the page on the MMC wiki :
http://mmc.drzeus.cx/wiki/SDIO
but cannot see a card using the Marvell 8xxx chipset : Can you give me
advice on which SDIO cards/module you are using.

Another point, do you know what the plans are for future SDIO wifi chips
support ?

The Marvell chip seems a bit particular as a wifi chip (802.11 stack
included in chip). Do you think that other chips are more or less
difficult to interface through SDIO ?

Is an Atheros-based card support planned ? (maybe more a madwifi people
question...)

Thanks for your help.
--
Nicolas Ferre


2007-11-23 16:40:20

by Pierre Ossman

[permalink] [raw]
Subject: Re: Wifi chips on SDIO interface

I'll just readd my reply again. :)

On Fri, 23 Nov 2007 16:13:18 +0100
Nicolas Ferre <[email protected]> wrote:

> I take advantage of this thread to ask a question about the SDIO cards
> you are using to test the stack.
>
> I look at the page on the MMC wiki :
> http://mmc.drzeus.cx/wiki/SDIO
> but cannot see a card using the Marvell 8xxx chipset : Can you give me
> advice on which SDIO cards you are using.

That whole site is unfortunately completely unmaintained. I'll probably pull the plug on the entire thing in the near future.

I'm afraid the only card I'm using actively is the Marvell 8686. Of my collection, it's the only one working well enough to do anything useful.

>
> Another point, do you know what the plans are for future SDIO wifi chips
> support ?
>

Not much. Atheros 6001 support is on its way (OpenMoko has this chip, so they're looking at it). The chip unfortunately seems to be a bit misdesigned when it comes to timeouts so it has problems initializing. I have no idea what the current status is.

I also have a Socket wifi card, but they haven't shown any interest in providing specs, so it's just a paperweight right now.

> The Marvell chip seems a bit particular as a wifi chip (802.11 stack
> included in chip). Do you think that other chips are more or less
> difficult to interface through SDIO ?

Well, full MAC is probably a must when it comes to SDIO. The bus is simply too slow and too high-latency to get any decent software MAC running.

Rgds
Pierre


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