kern/38172: Realtek 8139 C+ is not running in 100 MBit

[netbsd%luedke.org@localhost]

>Number:         38172
>Category:       kern
>Synopsis:       Realtek 8139 C+ is not running in 100 MBit
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Mar 05 12:10:00 +0000 2008
>Originator:     Frank Luedke
>Release:        NetBSD 4.0 RELEASE
>Organization:
>Environment:
NetBSD  4.0 NetBSD 4.0 (6420) #0: Fri Feb 22 14:08:14 CET 2008  
root@:/usr/src/sys/arch/i386/compile/6420 i386
>Description:
A system with four RTL8139C+ on board has installed fine. Network interfaces do 
only run on 10 MBit speed, even if 100BaseTX full-duplex is configured. 
Connection to another system is negotiated with 10 MBit and the 100 
MBit-status-LED of the LAN port does not lit.

The very same hardware running FreeBSD (m0n0wall, from http://m0n0.ch), Linux 
(RHEL 4) or Windows (XP) is running 100 MBit speed on all Realtek network 
interfaces. Therefore this must be a NetBSD issue.

# dmesg | grep re0
re0 at pci0 dev 11 function 0: RealTek 8139C+ 10/100BaseTX (rev. 0x20)
re0: interrupting at irq 5
re0: Ethernet address 00:90:0b:08:f8:e1
re0: using 64 tx descriptors
rlphy0 at re0 phy 0: Realtek internal PHY

# ifconfig -m re0
re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        
capabilities=3f80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx>
        enabled=0
        address: 00:90:0b:08:f8:e1
        media: Ethernet autoselect
        status: active
        supported Ethernet media:
                media 10baseT
                media 10baseT mediaopt full-duplex
                media 100baseTX
                media 100baseTX mediaopt full-duplex
                media autoselect
        inet 192.168.1.71 netmask 0xffffff00 broadcast 192.168.1.255
        inet6 fe80::290:bff:fe08:f8e1%re0 prefixlen 64 scopeid 0x1

The problem appears with the original 4.0 Kernel and also with my own kernel 
which supports only the installed hardware.
>How-To-Repeat:
Simply booting NetBSD with our without inserted network cable at boot time when 
using Realtek 8139C+.
>Fix:
Unknown.