[tulip-bug] Very slow performance with FA310TX

John William jw2357@hotmail.com
Sun, 24 Sep 2000 21:48:14 GMT


>From: Donald Becker <becker@scyld.com>
>On Sun, 24 Sep 2000, John William wrote:
>
> > I am having problems with a Netgear FA310TX card. Transfer rates to/from 
>the
...
>
>This sounds like either a
>    Duplex mismatch
>    Bad cable pairing, which works at 10BaseT but not 100baseTx

The card is connected to a FS105 10/100 switch on port #1. Both the switch 
and card indicate 100MBS and full duplex. They are connected with a 2 meter 
CAT5 pre-made cable. I'm 99% sure the hardware setup is good because I can 
pull the card and pop it into a Win98 box and get >8MB/sec with the same 
card/cable/switch.

> > I'm not even sure where to start looking for a problem since everything
> > works. The only hint that something might be wrong is under heavy load, 
>the
> > 310TX starts throwing a lot of frame errors:
> >
> > eth1      Link encap:Ethernet  HWaddr 00:A0:CC:39:B1:F9
> >           RX packets:530996 errors:0 dropped:0 overruns:0 frame:5735
> >           TX packets:495731 errors:1 dropped:0 overruns:1 carrier:0
>...
> > Under light load, no frame errors.
>
>Verify that that you are not forcing the duplex on this end.  That will 
>turn
>off autonegotiation, so your link partner think the link is
>100baseTx-half-duplex.

As far as I know I'm not forcing duplex. I am not passing any parameters to 
the tulip.o module. "tulip-diag" output shows:

tulip-diag.c:v2.03 7/31/2000 Donald Becker (becker@scyld.com)
http://www.scyld.com/diag/index.html
Index #1: Found a Lite-On 82c168 PNIC adapter at 0xfe00.
Port selection is MII, full-duplex.
Transmit started, Receive started, full-duplex.
  The Rx process state is 'Waiting for packets'.
  The Tx process state is 'Idle'.
  The transmit threshold is 1024.
Use '-a' or '-aa' to show device registers,
     '-e' to show EEPROM contents, -ee for parsed contents,
  or '-m' or '-mm' to show MII management registers.

So the card thinks it's full-duplex. The switch indicates full-duplex, so I 
have to assume it's correct.

After a little tweaking, outbound transfers from the machine are much 
better, but inbound is still very poor. Light network activity seems to be 
OK, but past a certain threshold performance really nose-dives and the 
"frame" errors start cropping up. The harder I try and "push" data into the 
machine the slower it gets (and the more frame error packets I get).

Is there anything else I can look at or try to do to narrow the problem 
down? When I can get some time on the machine, I will try and reboot it 
uniprocessor to see if there is a SMP problem but other than that I'm at a 
loss of how to proceed to debug this problem.

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