tx v2 error 0x6204<UNDERFLOW> - is this a new feature?

[Pyun YongHyeon]

On Mon, Jan 10, 2011 at 11:10 PM,  <fbsdmail at dnswatch.com> wrote:
> Greetings,
>  I have been receiving these messages on a recent 8.1/AMD64 install.
> src/ports && world/kern about a week ago. Here is a block from the most
> recent output:
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
> nfe0: tx v2 error 0x6204<UNDERFLOW>
>
> It appears to only occur when transmitting largish amounts of data
> across an NFS mount. I'm not sure where the MIN-threshold lies. But
> appears to be >=1.5Mb.
> This fresh 8.1/AMD64 is part of a largish server farm comprised of
> 7+ - 8.0 i386 servers. This one is the only AMD64. It is also the
> only AMD64. I experience this when mounting an 8.0/i386 server from
> this 8.1/AMD64. The i386 also has mounts on this 8.1/AMD64.
> relevant info:
> ### 8.0/i386
> 8.0-STABLE FreeBSD 8.0-STABLE #0: /usr/obj/usr/src/sys/UDNS01  i386
> Tyan 2-CPU MB
> 2 NIC's: fxp0 (only one in use)
> ### 8.1/AMD64
> FreeBSD 8.1-RELEASE-p2 #0: /usr/obj/usr/src/sys/XII amd64
> MSI K9N4 Ultra
> CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ (3511.34-MHz K8-class
> CPU)
> 1 NIC nfe0
> ### common to both:
> rc.conf
> nfs_client_enable="YES"
> nfs_reserved_port_only="YES"
> nfs_server_enable="YES"
>
> NIC's on both boards are 10/100's @100mbps
>
> Can anyone provide any insight as to why I should be receiving these
> messages on a fresh 8.1/amd64 install. Is 8.1 INcompatible with
> earlier versions?
>

No, I guess you're seeing one of unresolved nfe(4) issues.
By chance, are you using forced media configuration instead of
auto-negotiation?
Posting both dmesg and "ifconfig nfe0" output would be useful.

> Thank you for all your time and consideration.
>
> --Chris