iMac G3 IPv6 issue

iMac G3 IPv6 issue

[Aurélien GÉRÔME]

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Hi there,

Since it is kernel related, I think it is the best place to ask.

I installed Debian Sid on a BlueBerry iMac G3.

[20:51:54|3|root@arwen:~]# cat /proc/cpuinfo
processor       : 0
cpu             : 740/750
temperature     : 52 C (uncalibrated)
clock           : 350MHz
revision        : 2.2 (pvr 0008 0202)
bogomips        : 696.32
machine         : PowerMac2,1
motherboard     : PowerMac2,1 MacRISC Power Macintosh
detected as     : 66 (iMac FireWire)
pmac flags      : 00000005
L2 cache        : 512K unified
memory          : 128MB
pmac-generation : NewWorld

[20:54:17|3|root@arwen:~]# uname -a
Linux arwen 2.6.8.1 #1 Sat Aug 21 15:46:55 CEST 2004 ppc GNU/Linux

I put IPv6 support, but the console is flooded by a lot of:

printk: 16 messages suppressed.
hw tcp v6 csum failed
printk: 11 messages suppressed.
hw tcp v6 csum failed
printk: 5 messages suppressed.
hw tcp v6 csum failed
printk: 5 messages suppressed.
hw tcp v6 csum failed
printk: 5 messages suppressed.
hw tcp v6 csum failed
printk: 5 messages suppressed.
hw tcp v6 csum failed
printk: 7 messages suppressed.
hw tcp v6 csum failed

However, IPv6 works, and IPv4 packets do not have this kind of issue.

The network card is a Sun Gem. It is kind of weird to see bad packets.

Attached is my /proc/config.gz.

Is anyone aware of this issue?

Bests.
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BOFH excuse #423: It's not RFC-822 compliant.

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Re: iMac G3 IPv6 issue

[Aurélien GÉRÔME]

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Oops, sorry, config.gz attached.

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Re: iMac G3 IPv6 issue

[David Woodhouse]

On Sun, 2004-09-12 at 15:39 +0200, Aurélien GÉRÔME wrote:
> I put IPv6 support, but the console is flooded by a lot of:
> hw tcp v6 csum failed
> However, IPv6 works, and IPv4 packets do not have this kind of issue.
> The network card is a Sun Gem. It is kind of weird to see bad packets.

I use the sungem in a similar machine with IPv6, and haven't seen any
problems. Can you tcpdump from a different machine on the network and
confirm whether these reported bad checksums really are happening or if
it's the fault of the hardware/driver?

-- 
dwmw2

Re: iMac G3 IPv6 issue

[Aurélien GÉRÔME]

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On Sun, Sep 12, 2004 at 06:57:31PM +0100, David Woodhouse wrote:
> On Sun, 2004-09-12 at 15:39 +0200, Aurélien GÉRÔME wrote:
> > I put IPv6 support, but the console is flooded by a lot of:
> > hw tcp v6 csum failed
> > However, IPv6 works, and IPv4 packets do not have this kind of issue.
> > The network card is a Sun Gem. It is kind of weird to see bad packets.
> 
> I use the sungem in a similar machine with IPv6, and haven't seen any
> problems. Can you tcpdump from a different machine on the network and
> confirm whether these reported bad checksums really are happening or if
> it's the fault of the hardware/driver?

I have 2 machines on the same switch and an IPv6 ssh connection between
them.

"tcpdump -a -i eth0 -v" on both machines shows [tcp sum ok].

The ssh link is an IPv6 one, arwen is the faulty machine, and aragorn a
sane one.

arwen has also a ppp0 interface, no infamous [bad tcp cksum ....!]
appears, on lo interface too. All is reported [tcp sum ok].

But during this time, the kernel keeps flooding the console with these
"hw tcp v6 csum failed"...

Moreover, like I said, the IPv6 networking works fine.

In that case, is it the driver fault?

I wonder if it is possible to print the checksum and the interface with
the LIMIT_NETDEBUG(printk(KERN_DEBUG "hw tcp v6 csum failed\n"));.

Bests.
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        _,met$$$$$gg.        Aurélien GÉRÔME
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   ,g$$P""       """Y$$.".   Unix Sys & Net Admin
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             `""""            (8___8)     /`\_`>  <_/ \
                               `---`      \__/'---'\__/
BOFH excuse #88: Boss' kid fucked up the machine

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Re: iMac G3 IPv6 issue

[David S. Miller]

On Sun, 12 Sep 2004 18:57:31 +0100
David Woodhouse <dwmw2@infradead.org> wrote:

> On Sun, 2004-09-12 at 15:39 +0200, Aurélien GÉRÔME wrote:
> > I put IPv6 support, but the console is flooded by a lot of:
> > hw tcp v6 csum failed
> > However, IPv6 works, and IPv4 packets do not have this kind of issue.
> > The network card is a Sun Gem. It is kind of weird to see bad packets.
> 
> I use the sungem in a similar machine with IPv6, and haven't seen any
> problems. Can you tcpdump from a different machine on the network and
> confirm whether these reported bad checksums really are happening or if
> it's the fault of the hardware/driver?

One thing that's interesting is that the sungem and sunhme
drivers are the only two in the whole tree that support
IPV6 checksum offload.  Like David, I have never seen this
problem on Sparc systems using the GEM chip and this
driver.

Re: iMac G3 IPv6 issue

[Aurélien GÉRÔME]

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On Sun, Sep 12, 2004 at 03:58:50PM -0700, David S. Miller wrote:
> On Sun, 12 Sep 2004 18:57:31 +0100
> David Woodhouse <dwmw2@infradead.org> wrote:
> 
> > On Sun, 2004-09-12 at 15:39 +0200, Aurélien GÉRÔME wrote:
> > > I put IPv6 support, but the console is flooded by a lot of:
> > > hw tcp v6 csum failed
> > > However, IPv6 works, and IPv4 packets do not have this kind of issue.
> > > The network card is a Sun Gem. It is kind of weird to see bad packets.
> > 
> > I use the sungem in a similar machine with IPv6, and haven't seen any
> > problems. Can you tcpdump from a different machine on the network and
> > confirm whether these reported bad checksums really are happening or if
> > it's the fault of the hardware/driver?
> 
> One thing that's interesting is that the sungem and sunhme
> drivers are the only two in the whole tree that support
> IPV6 checksum offload.  Like David, I have never seen this
> problem on Sparc systems using the GEM chip and this
> driver.

The board is this:
0002:02:0f.0 Ethernet controller: Apple Computer Inc. UniNorth GMAC (Sun
GEM)

So, it is Apple stuff wrapping a Sun GEM chip. The issue may come from
that. Anyway, I am going to dig in the source code to find out.

Cheers.
-- 
        _,met$$$$$gg.        Aurélien GÉRÔME
     ,g$$$$$$$$$$$$$$$P.     Free Software Developer
   ,g$$P""       """Y$$.".   Unix Sys & Net Admin
  ,$$P'              `$$$.
',$$P       ,ggs.     `$$b:  Web: https://www.roxor.be/
`d$$'     ,$P"'   .    $$$   Mail: ag@roxor.be
 $$P      d$'     ,    $$P   GPG Key ID: 03E1A172
 $$:      $$.   -    ,d$$'
 $$;      Y$b._   _,d$P'    ))  GNU  ((   /   Linux
 Y$$.    `.`"Y$$$$P"'      //         \\
 `$$b      "-.__          ((__,-"""-,__))     .---.
  `Y$$b                    `--)~   ~(--`     /     \
   `Y$$.      Debian      .-'(       )`-.    \.@-@./
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         `"Y$b._              |     |      | \     )|_
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                               `---`      \__/'---'\__/
BOFH excuse #113: Root nameservers are out of sync

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Re: iMac G3 IPv6 issue

[David S. Miller]

On Mon, 13 Sep 2004 01:17:31 +0200
Aurélien GÉRÔME <ag@roxor.be> wrote:

> The board is this:
> 0002:02:0f.0 Ethernet controller: Apple Computer Inc. UniNorth GMAC (Sun
> GEM)
> 
> So, it is Apple stuff wrapping a Sun GEM chip. The issue may come from
> that. Anyway, I am going to dig in the source code to find out.

It would be interesting if some other iMac users can reproduce
this too.

BTW, your signature is quite huge, could you trim it down
or (alternatively) not attach it when posting to this list?
Thanks a lot.

Re: iMac G3 IPv6 issue

[Aurélien GÉRÔME]

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On Sun, Sep 12, 2004 at 04:28:47PM -0700, David S. Miller wrote:
> On Mon, 13 Sep 2004 01:17:31 +0200
> Aurélien GÉRÔME <ag@roxor.be> wrote:
> 
> > The board is this:
> > 0002:02:0f.0 Ethernet controller: Apple Computer Inc. UniNorth GMAC (Sun
> > GEM)
> > 
> > So, it is Apple stuff wrapping a Sun GEM chip. The issue may come from
> > that. Anyway, I am going to dig in the source code to find out.
> 
> It would be interesting if some other iMac users can reproduce
> this too.

If it is reproducible on this board (actually, it is built-in on
this machine), then it is really specific to this one. PowerBooks and
iBooks have also Sun GEM, and it does not occur.

> BTW, your signature is quite huge, could you trim it down
> or (alternatively) not attach it when posting to this list?
> Thanks a lot.

I am sorry, please accept my apologies if I have bothered you or
others with it. ;)

Bests.

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