Isaac Whatever

Gentoo linux forms the base of my "networked inventory control appliance", so I've been installing Gentoo on a number of older PCs we have lying around.

Older PCs are great for this project because it doesn't require much in the way of computing power, and they're cheap and generally well-supported in linux.

I expected that installing Gentoo on an old Dell Dimension 2100 would be a simple process, but this dell has a network card that has been causing me some trouble.

Lspci reports the card as "Ethernet controller: Davicom Semiconductor, Inc. 21x4x DEC-Tulip compatible 10/100 Ethernet (rev 31)". The Gentoo boot disc loads both the tulip and dmfe modules, and seems to work perfectly fine.

When configuring the kernel myself I chose the driver which corresponded to the tulip module, listed in menuconfig as "DECchip Tulip (dc2114x) PCI support". I thought that since the lspci showed the card as 21x4x that "2114x" would probably work, and the Gentoo boot/install disc is usually spot on in its driver choices.

And it did, for about 30 seconds after a reboot. Then it quit. I could get it working for another 30 second spurt by unplugging the LAN cable and plugging it back in.

I started the Google-Fu and found this thread on the ubuntu forums where they advised blacklisting the tulip module and loading only the dmfe.

Going back through menuconfig I turned off my earlier option (DECchip Tulip (dc2114x) PCI support) and instead picked "Davicom DM910x/DM980x support". This choice corresponds to the dmfe module. Then I recompiled the kernel and rebooted.

Did it work? Well, partially. I lost my connection for a bit after a reboot, but it does work fine most of the time now. I suppose I'll use it as a testing machine and keep my eye out for a salvageable NIC.

To recap, for anyone who finds this site looking for the solution to the same problem...
System:

• Dell Dimension 2100
• Gentoo Linux 2006.1
• kernel version: 2.6.19-gentoo-r5
  
• lspci output: Ethernet controller: Davicom Semiconductor, Inc. 21x4x DEC-Tulip compatible 10/100 Ethernet (rev 31)

Problem:

• Loss of network connectivity approx. 30 seconds after reboot.
• DHCP works fine at boot - can be misleading.

Solution (for those like me, who want the driver in the kernel, not a module):

1. In menuconfig, deselect the other tulip related drivers.
2. Use the option for "Davicom DM910x/DM980x support".
3. make && make modules_install
4. cp arch/i386/boot/bzimage to /boot/{your kernel}
5. adjust grub if necessary
   
6. reboot

Of course, if you'd like it as a module, use the excellent howto on the ubuntu forums . And remember, you might need to unload and reload that module twice for it to work.

Really, you should probably just go get a new NIC.

Labels: drivers, gentoo, irritation, linux