[vortex-bug] Tx underrun

[Remco van de Meent]

Hey,

When doing large filetransfers from one network to another, with a Pentium
166Mhz machine with IP-Masquerading and Linux kernel 2.2.15 as 'router', I
occasionally get a message like this:

  eth0: Transmit error, Tx status register 90.

eth0 is a Vortex card with 3c59x.c:v0.99x (x being H or L), eth1 is handled
by the de4x5 network driver, both running at 100Mbps/half-duplex.

I guess this error message, causing that network appearing to be down for
some time or until I rmmod/modprobe the 3c59x driver, is caused by a Tx
underrun (`not enough PCI bus bandwidth') ? The machine contains an (quite
ancient) Asus P/I-P55TP4N motherboard, with 'latest' Award BIOS. For your
information, I added the vortex-diag output (during normal operation) at the
bottom.

When I lower the transfer-rate, for example by flooding the network attached
to eth1, it seems no errors occur.

I don't know if it's possible to solve this problem in software by some
tweaking of the 3c59x driver, or should I just live with it (or buy another
network card) ?


Thanks in advance for your advice,

Kind regards,

Remco.

PS It would be great if you could Cc any answer to me, because I am not on
   this list (though I read through the mailinglist archives of course).


------
# ./vortex-diag -a
vortex-diag.c:v2.00 4/19/2000 Donald Becker (becker@scyld.com)
 http://www.scyld.com/diag/index.html
Index #1: Found a 3Com 3c595 Vortex 10/100baseTx adapter at 0xe400.
The Vortex chip may be active, so FIFO registers will not be read.
To see all register values use the '-f' flag.
Initial window 7, registers values by window:
  Window 0: 0000 0000 0000 0000 0000 00bf 0000 0000.
  Window 1: FIFO FIFO 0000 2000 8000 00ff 3ffc 2000.
  Window 2: 2000 edaf c516 0000 0000 0000 00de 4000.
  Window 3: 001b 0041 0000 0000 e10a bfff 3fff 6000.
  Window 4: 0000 02d2 0000 0c80 0000 8882 0200 8000.
  Window 5: 1ffc 1ffc 00de 1ffc 0007 02de 00de a000.
  Window 6: 0000 0000 0000 ab00 0000 3ef6 0000 c000.
  Window 7: 0000 0000 0000 0000 8000 00ff 0000 e000.
Vortex chip registers at 0xe400
  0xE410: **FIFO** 00000000 00008000 *STATUS*
  0xE420: ffffffff ffffffff ffffffff ffffffff
  0xE430: ffffffff ffffffff ffffffff ffffffff
 Indication enable is 00de, interrupt enable is 02de.
 No interrupt sources are pending.
 Transceiver/media interfaces available:  100baseTx 10baseT.
Transceiver type in use:  100baseTX.
 MAC settings: half-duplex.
Maximum packet size is 0.
 Station address set to 00:20:af:ed:16:c5.
 Configuration options 4000.