Subject: Re: Intel i82547 performance problems in wm(4)
To: Matthias Scheler <>
From: HITOSHI Osada <>
List: tech-net
Date: 07/13/2004 01:42:32
At Mon, 12 Jul 2004 17:34:50 +0200,
Matthias Scheler <> wrote:
> 	Hello,
> while examing PR kern/23782 I've noticed an intesting detail. Here is
> what the result of auto negotiation between an Intel i82540EM and
> my 3Com GbE switch:
>         media: Ethernet autoselect (1000baseT full-duplex)
> And here is what the Intel i82547EI detects:
>         media: Ethernet autoselect (1000baseT full-duplex,flowcontrol,rxpause,tx
> Is it possible that auto negotiation is broken somehow? 

"flowcontrol,rxpause,txpause" means "IEEE 802.3x flow control enable,
sending/receiving PAUSE frame". It is normal. Your auto negotiation is
successfully completed.

> I've tried to
> use manual configuration with the i82547EI but it completely killed
> the link.

In 1000BASE-T, auto negotiation is mandatory. A manual setup cannot be performed.

I think i82547 requires some special FIFO handling for best
performance. Linux driver(e1000-5.2.52) tunes FIFO parameters in