Re: recent MFC code to 6-STABLE kills ipv6

On Mon, 2005-11-07 at 18:05 -0600, Mark Linimon wrote:
> On Mon, Nov 07, 2005 at 11:20:43AM -0800, Sean McNeil wrote:
> > > The dc(4) driver supports a whole bunch of different chips. It really
> > > really really matters that you tell us exactly which one you have.
> > 
> > How could this possibly matter?  There were no changes to the dc0 driver
> > from Nov 1st to present.
> 
> The essence of good bug reports is to report any fact that might _possibly_
> be relevant.  It helps to quickly eliminate possibilities.
> 
> This isn't just true for FreeBSD; I have fought this battle for decades
> in this profession.  Sometimes even as I'm composing a bug report I find
> myself walking through my list of unstated assumptions about what the
> problem "must" be.  Half the time one of my assumptions is bogus.
> 
> This is not a criticism of the OP, this is just how engineering works --
> if we presuppose too much about the problem, rather than just reporting
> symptoms, we can wind up going around in circles.
> 
> The PR database has many hundreds of such entries, unfortunately.

Guess I sounded too defensive on that point.  I was curious, though, as
we are really tracking down a change that killed IPv6 in a particular
way.  I've been guilty of overlooking evidence myself in the past, but I
honestly do not see the relevance in this case.

In the name of full disclosure, here is my hardware:

Gigabyte K8 Triton series with 3800+ 2x Athlon, 2GB DDR 400 RAM and
builtin sk0 Marvell gigE for internal network.  Old Linksys dc0 PCI card
that I can look at to get additional info if required.  dmesg info:

CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ (2080.20-MHz
K8-class CPU)
  Origin = "AuthenticAMD"  Id = 0x20f32  Stepping = 2

Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT>
  Features2=0x1<SSE3>
  AMD Features=0xe2500800<SYSCALL,NX,MMX+,<b25>,LM,3DNow+,3DNow>
  Hyperthreading: 2 logical CPUs
real memory  = 2147418112 (2047 MB)
avail memory = 2062999552 (1967 MB)
ACPI APIC Table: <Nvidia AWRDACPI>
...
dc0: <ADMtek AN985 10/100BaseTX> port 0xa400-0xa4ff mem
0xf5005000-0xf50053ff irq 17 at device 9.0 on pci2
miibus0: <MII bus> on dc0
ukphy0: <Generic IEEE 802.3u media interface> on miibus0
ukphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
dc0: Ethernet address: 00:03:6d:1a:b1:9b
skc0: <Marvell Gigabit Ethernet> port 0xa800-0xa8ff mem
0xf5000000-0xf5003fff irq 19 at device 11.0 on pci2
skc0: Marvell Yukon Lite Gigabit Ethernet rev. (0x9)
sk0: <Marvell Semiconductor, Inc. Yukon> on skc0
sk0: Ethernet address: 00:14:85:85:27:b3
miibus1: <MII bus> on sk0
e1000phy0: <Marvell 88E1000 Gigabit PHY> on miibus1
e1000phy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX,
1000baseTX-FDX, auto
...

Of additional interest is the fact that I can actually ping6 both
interfaces from my Powerbook running Tiger 10.4.3.  It is connected on
the sk0 side.

Cheers,
Sean