Re: Marvell Libertas wifi

[Dan Williams <dcbw@redhat.com>]

On Fri, 2006-12-08 at 01:03 -0500, Alex Deucher wrote:
> On 12/7/06, Dan Williams <dcbw@redhat.com> wrote:
> > On Thu, 2006-12-07 at 12:32 -0500, Alex Deucher wrote:
> > > I just wanted to check on the status of the libertas driver from
> > > Marvell for the OLPC project.  I haven't really been able to find out
> >
> > The driver needs quite a bit of love.  It's only been used for embedded
> > devices so far and has quite a few NDIS-isms sprinkled throughout.  It's
> > also something like 30,000 LoC, which is completely bogus.  There's no
> > reason it should be that large given that it's a FullMAC-type part.
> >
> > We're slowly working on cleaning it up for submission to the kernel.
> > That process will probably take until after the holidays.  We are
> > removing unused code/defines, cleaning up WEXT compliance, making
> > operations like association and scanning asynchronous, converting
> > private IOCTLs to debugfs, fixing the power-saving code, and adding
> > draft 802.11s wireless mesh functionality to the firmware and the
> > driver.
> >
> > Are you developing a device based on the 8388?  AFAIK, the chip does not
> > appear in any consumer devices that are generally available to the
> > public, and certainly isn't sold to Linksys or DLink for consumer USB
> > dongles.  It does show up in embedded situations like the Nokia N80
> > mobile phone and a few other small gadgets like that.
> >
> > > much about this driver other than the commits to the olpc and
> > > infradead libertas git trees.  The olpc laptop uses the usb interface
> >
> > Correct; the 8388 module is connected directly to the USB traces coming
> > out of the 5536 Geode companion chip on the OLPC motherboard.
> >
> > > and that seems to be what is supported at the moment (although some
> > > comments in the code allude to pci and sdio interfaces as well).  Does
> >
> > Yes; the part evidently has other interface variants, though code for
> > those variants was not provided in the initial driver sources which
> > Marvell GPL-ed in April.
> >
> > > anyone know what the plan is for merging this driver into mainline?
> > > What about pci support?  Did Marvell donate any code for the PCI
> > > interface? If not how hard would it be to add PCI support?  I
> >
> > No code for PCI was donated, and we don't have any 8388 PCI cards at
> > OLPC.
> >
> > > requested databooks from Marvell months ago, but never got anywhere.
> > > I'd like to see better support for this chip and would be willing to
> > > help out.  Any updates would be much appreciated.
> >
> > Be aware that I _think_ there are a few chips in the Libertas line; we
> > are using the 8388.  The current driver only supports that specific
> > part.
> >
> > That said, if you've got hardware, we'd love patches, certainly accept
> > patches that provided PCI support and fixed bugs in the driver.  We may
> > also be able to provide USB 8388 reference dongles for people willing to
> > help out with the development of the driver.
> >
> 
> Yes, that appears to be the case.  I just wasn't sure how
> similar/dissimilar they are.  I have a 11ab:1fa7 on my motherboard,
> and I've seen quite a few Marvel chips floating around on cardbus and
> pci cards.  I'm hoping the cores are pretty similar and one could just
> add some pci glue to make the olpc driver work.  Does anyone at the
> olpc have any contacts at Marvell that could clarify the situation or
> might know if they are willing to release the code for the pci
> variants, etc.?

What's the numbers on the chip?  We know that the _8338_ part (which
may/may not be part of the Libertas family, we're not sure) doesn't
work, and that's shipping on USB dongles from Linksys.  If you could get
a bit more info off the surface of the chip, that would help.  The 8338
part, for example, has a different firmware load sequence and a
different sized RAM than the 8388 which we're using, and is incompatible
with the current driver.

Dan

> Thanks,
> 
> Alex
> 
> > Cheers,
> > Dan
> >
> > > Thanks,
> > >
> > > Alex
> > >
> > > PS, please CC: me on replies as I'm not on this list.