Marvell YukonII Status Update?

[Pyun YongHyeon]

On Sat, Jul 01, 2006 at 02:54:01AM -0500, Nikolas Britton wrote:
 > On 7/1/06, Pyun YongHyeon <pyunyh at gmail.com> wrote:
 > >On Sat, Jul 01, 2006 at 01:33:51AM -0500, Nikolas Britton wrote:
 > > > On 7/1/06, Pyun YongHyeon <pyunyh at gmail.com> wrote:
 > > > >On Fri, Jun 30, 2006 at 11:39:14PM -0500, Nikolas Britton wrote:
 > > > > > On 6/30/06, Pyun YongHyeon <pyunyh at gmail.com> wrote:
 > > > > > >On Thu, Jun 29, 2006 at 10:53:52PM -0500, Nikolas Britton wrote:
 > > > > > > > Anyone know what's going on with YukonII support in FreeBSD,
 > > > > > > > specifically the Marvell chips used in PCI-Express add-on cards?
 > > > > > > >
 > > > > > > > Last I checked somebody was developing an experimental driver 
 > > and
 > > > > > > > Marvell had just released the code to their FreeBSD 5.x/6.x 
 > > driver:
 > > > > > > > mykbsd60x86-8.12.2.3.tar (bindary kmod package)
 > > > > > > > mykbsd60x86-8.12.1.3-src.tgz (source code)
 > > > > > > >
 > > > > > >
 > > > > > >I don't know current status of the driver. ATM FreeBSD YukonII
 > > > > > >driver has stability issues and the driver needs big cleanups
 > > > > > >if we import the driver into src tree. But I wouldn't do the
 > > > > > >job and I'll spend my spare time to other thing.
 > > > > > >I know, from my previous experience(sk(4), stge(4)), how
 > > > > > >difficult to write a driver without a document and how hard to
 > > > > > >write a correct driver without knowing hardware internals. I'm
 > > > > > >sure there are many developers eager to write YukonII driver if
 > > > > > >they can access the hardware documentation. However I think there
 > > > > > >is no possibility that Marvell releases their chip documentations.
 > > > > > >
 > > > > >
 > > > > > Marvell will give you the docs if you sign an NDA, I know it's 
 > > stupid
 > > > > > but I think it's the only way... unless we vote with the wallet... 
 > > Who
 > > > > > has PCI-Express gigabit NIC cards that meet the following criteria?:
 > > > > >
 > > > > > a) Supported by FreeBSD.
 > > > > > b) Unencumbered documentation.
 > > > > > c) Checksum offloading.
 > > > > >
 > > > >
 > > > >There are many PCIe GigE hardwares upported by em(4) or bge/bce(4).
 > > > >AFAIK the only hardware features not supported by em(4)/bge(4) driver
 > > > >is TSO. And hardwares supported by em(4) also have a capability to
 > > > >offload IPv6 checksumming too but it's not yet supported by the driver.
 > > > >
 > > >
 > > > Will TCP Segmentation Offloading help if you already use a 9000 byte
 > > > mtu, and is it going to be supported, someday, with em(4)/bge(4)?...
 > > > I'm mostly clueless about TSO.
 > > >
 > >
 > >Since not all hardwares support JUMBO frame and the maximum MTU
 > >for the JUMBO frame varies among vendors/chipsets TSO would be
 > >better suited for interoperability.
 > >
 > >I'm really want to see TSO support in our drivers. See the
 > >following URL to see TSO effect in NetBSD wm(4) driver.
 > >http://marc.theaimsgroup.com/?t=111662994600001&r=1&w=2
 > >
 > 
 > I see... A poor mans jumbo frames, but only works with the sender,

You may have to get a NIC that supports JUMBO frames on receiver
too unless your switch/bridge system fragments the JUMBO frames
into standard MTU frames.

 > correct? If NetBSD supports it can't we more or less just copy and
 > paste the code to FreeBSD? I know it's never that simple but...
 > 

Yes, we may borrow the code from NetBSD implementation but I can't
sure we can just copy it. I guess we need careful reexamination
the TSO effect on our TCP stack.

-- 
Regards,
Pyun YongHyeon