[3c509] RE: Problem with 3c905b after Linux kernel upgrade

martin@easysoft.com martin@easysoft.com
Tue Jan 15 04:10:01 2002

On Sun Jan 13 19:05:01 2002, I said:

> I have a 3c509b working fine in linux 2.2.18 but when booting into
> 2.4.17 networking stops working. I believe I have the same
> kernel options enabled.
> >From 2.4.18 a ping seems to send a packet out but nothing
> comes back. I can see the ping transmitting as my ascend pipeline
> LEDs flash. When I look at ifconfig output it shows packets
> transmitted and received but no network programs are working.
> I noticed one difference between the two.
> In 2.2.18 I only get one:
> eth0: Setting Rx mode to 1 addresses.
> in dmesg but in 2.4.17 I get
> eth0: Setting Rx mode to 0 addresses.
> eth0: Setting Rx mode to 1 addresses.
> Apart from that the two kernels seem to pick a different
> interrupt old 12, new 5.
> Any ideas?

I have finally found the problem. Linux 2.4.17 has plug and play support for
ISA devices (on by default). This is a new option in the Linux kernel that was
not in 2.2.18. My BIOS has Plug and Play enabled but IRQ 12 reserved
for ISA devices. When I disabled plug and play in the 2.4.18 kernel the 3c509
driver loaded fine and discovered the board was on IRQ 12.

With plug and play enabled in the kernel the 3c509 driver was using IRQ 5 and I
could not appear to make it change its mind (even with irq=12 on the insmod line
or with ether=12,,eth0 at the boot prompt for a built in driver).

Hope this helps someone else.

Martin J. Evans
Easysoft Ltd, UK