Re: status of libertas_tf + sdio?

From: Dan Williams <dcbw@redhat.com>
To: Vasily Khoruzhick <anarsoul@gmail.com>
Cc: James Cameron <quozl@laptop.org>,
	Andreas Kemnade <andreas@kemnade.info>,
	linux-wireless@vger.kernel.org, libertas-dev@lists.infradead.org
Subject: Re: status of libertas_tf + sdio?
Date: Wed, 11 Dec 2013 16:41:53 -0600	[thread overview]
Message-ID: <1386801713.17188.59.camel@dcbw.foobar.com> (raw)
In-Reply-To: <CA+E=qVdFfvXVXJfbnKj6sxfsE6qDxQ6YZ5-eSKOmopVEodxM0A@mail.gmail.com>

On Thu, 2013-12-12 at 00:21 +0300, Vasily Khoruzhick wrote:
> On Wed, Dec 11, 2013 at 11:55 PM, James Cameron <quozl@laptop.org> wrote:
> > On Wed, Dec 11, 2013 at 11:10:50AM +0300, Vasily Khoruzhick wrote:
> >> On Tue, Dec 10, 2013 at 5:27 AM, James Cameron <quozl@laptop.org> wrote:
> >> > On Mon, Dec 09, 2013 at 12:38:28PM +0300, Vasily Khoruzhick wrote:
> >> >> On Mon, Dec 9, 2013 at 7:18 AM, James Cameron <quozl@laptop.org> wrote:
> >> >> > On Fri, Dec 06, 2013 at 01:40:00PM +0300, Vasily Khoruzhick wrote:
> >> >> >> Out of curiosity,
> >> >> >>
> >> >> >> Does anyone know if it's possible to get thin firmware for 8686 with
> >> >> >> SPI interface?
> >> >> >
> >> >> > What happens when you try?
> >> >>
> >> >> How? There's no tf available for 8686 with SPI interface.
> >> >
> >> > How do you know that?  Are you saying that SPI support was removed
> >> > from firmware during the conversion from fat to thin?
> >>
> >> Err, there's no lbtf_spi.bin file.
> >
> > Basing decisions on the names of files rather than the code they
> > may contain seems rather limiting.
> >
> > In the absence of evidence, there's a possibility that SPI support
> > remained.
> 
> But fat firmware differs for SPI and SDIO

Correct.  AFAIK (and I could be wrong, I haven't been involved for a few
years) CozyBit only did the thin firmware for OLPC-specific deployments
of the usb8388 and sd868x parts which were included in OLPC devices, to
support the mesh networking protocols used by OLPC.  None of those parts
used SPI; and thus I would not expect there to be a thin firmware for
any SPI parts.  I'd love to be proved wrong though.

Each bus type uses different firmware, so yes, you'd need both a helper
firmware and a main firmware that contains code specific to the bus
type.

Dan

> >> >> > How are you downloading firmware over SPI?
> >> >>
> >> >> See drivers/net/wireless/libertas/if_spi.c, but it's for fat
> >> >> firmware
> >> >
> >> > What happens if you send the thin firmware instead?
> >>
> >> I have no thin firmware for 8686 with SPI interface
> >
> > What happens if you send the thin firmware for SDIO interface to the
> > device using the fat firmware helper for SPI interface?
> >
> > I don't have an SPI setup to test, but I gather you do.
> 
> OK, I'll try.
> 
> >> >> > I'm not aware of a second stage firmware download helper
> >> >> > specific to the SPI mode.
> >> >>
> >> >> What's a second stage firmware download helper?
> >> >
> >> > File sd8686_helper.bin, we use it in Open Firmware with SDIO 8686 on
> >> > OLPC XO.
> >> >
> >> > For SPI, which we don't use, I see if_spi.c uses gspi8686_v9_helper.bin
> >> >
> >> > I was wrong; I am now aware of a second stage firmware downloader
> >> > helper specific to the SPI mode.  I hadn't looked before.
> >> >
> >> >> > I think it is not possible without firmware engineering.
> >> >>
> >> >> Yeah, just hoped that Marvell already did it. It's a pity that
> >> >> firmware source code isn't available :(
> >> >
> >> > Cozybit did the thin firmware, if I recall correctly.
> >>
> >> Do you think it makes sense to contact them?
> >
> > I don't think it makes sense to ignore them, but I don't wish to
> > speculate further.
> 
> OK, thanks!
> 
> Regards
> Vasily
> 
> > --
> > James Cameron
> > http://quozl.linux.org.au/
> 
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