recent stability problems with fxp driver

[John Polstra]

On 15-Sep-2003 Vivek Khera wrote:
> I've a handful of 1550s as well.  None of them exhibit any problems
> speaking to the network as connected to Netgear 10/100 switches (well,
> one did at one time, but it turned out to be a motherboard hardware
> fault).  One of the servers' sole duty is to take backups of various
> large files on other machines on the LAN and it works just fine.

Interesting!  Thanks for that info.

> Here's the pciconf output from that 'backup' machine:
> 
> fxp0 at pci0:1:0:  class=0x020000 card=0x00da1028 chip=0x12298086 rev=0x08 hdr=0x00
>     vendor   = 'Intel Corporation'
>     device   = '82557/8/9 EtherExpress PRO/100(B) Ethernet Adapter'
>     class    = network
>     subclass = ethernet
> fxp1 at pci0:2:0:  class=0x020000 card=0x00da1028 chip=0x12298086 rev=0x08 hdr=0x00
>     vendor   = 'Intel Corporation'
>     device   = '82557/8/9 EtherExpress PRO/100(B) Ethernet Adapter'
>     class    = network
>     subclass = ethernet

Yes, that's exactly the same as my 1550 system.

> I wouldn't rule out hardware.  The Dell diagnostics are amazingly good
> at finding hardware faults.

I'll check into that.  I've never run the Dell diagnostics before.

> It could just as well be your switch/hub.  I have an old 5-port hub
> that none of my fxp ports will speak to, but the de and sis ones do.

I don't think anything the switch does should be able to cause SCB
timeouts and DMA timeouts.  But just to be sure, I tried again using a
Dell managed 10/100/1000 Mbit switch.  I still get the same failures
with that switch, too.  I also tried disabling flow control on the
switch, but it didn't help.

Doug Ambrisko told me he's had similar problems with certain fxp
devices and was able to fix them by patching a few bits in the EEPROMs
based on the EEPROM contents of a card that works.  It sounds like he
found the bits to patch more or less by trial and error.  (There's a
posting from him about it in the mailing list archives somewhere.)
I'm going to try it, but haven't had time yet to do it safely.  I have
a Dell desktop machine with exactly the same revision of 82559 in it
that works perfectly, so I was hoping to use it as the reference.
Unfortunately, its EEPROM contents differ from those on the 1550 in
several places, even ignoring the expected differences in the stored
MAC addresses.  So it's not at all obvious what to change and what to
leave alone.  If it were a NIC I'd be willing to trash it, but I'm
naturally more cautious with devices that are on the motherboard.

John