Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 27 Feb 2003 10:33:46 -0800 (PST)
From:      wpaul@FreeBSD.ORG (Bill Paul)
To:        dcs@tcoip.com.br (Daniel C. Sobral)
Cc:        jlemon@FreeBSD.org, ru@FreeBSD.org, src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org
Subject:   Re: cvs commit: src/sys/dev/fxp if_fxp.c if_fxpreg.h if_fxpvar.h
Message-ID:  <20030227183346.657C937B401@hub.freebsd.org>
In-Reply-To: <3E5E49A1.9050507@tcoip.com.br> from "Daniel C. Sobral" at "Feb 27, 2003 02:23:45 pm"

next in thread | previous in thread | raw e-mail | index | archive | help

> root@piratinga:/usr/src/sbin/ifconfig# ifconfig fxp2 rxcsum
> root@piratinga:/usr/src/sbin/ifconfig# ifconfig fxp2 txcsum
> root@piratinga:/usr/src/sbin/ifconfig# ifconfig -m fxp2
> fxp2: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>          options=8<VLAN_MTU>
>          capability list:
>                  =b<RXCSUM,TXCSUM,VLAN_MTU>
>          ether 00:02:b3:8f:30:41
>          media: Ethernet autoselect (100baseTX <full-duplex>)
>          status: active
>          supported media:
>                  media autoselect
>                  media 100baseTX mediaopt full-duplex
>                  media 100baseTX
>                  media 10baseT/UTP mediaopt full-duplex
>                  media 10baseT/UTP
>                  media none
>                  media 100baseTX mediaopt hw-loopback
> root@piratinga:/usr/src/sbin/ifconfig#
> 
> > Jonathan forgot to document the "rxcsum", "txcsum", and
> > "netcons" capabilities in the ifconfig(8) manpage.
> 
> Honestly, I thought this would have been configured with mediaopt. At 
> any rate, it doesn't work.

Er... look. The checksum offload capabilities are turned on by default,
if your chip supports them, which it appears it does. Also, please try
and remember just how bent I can get at someone who says "it doesn't
work" without defining in precise detail just what "it" is and what
"doesn't work" implies.

Do you mean that using ifconfig to twiddle the capabilities doesn't
seem to make any difference?
Do you mean that the cards aren't working with the updated driver (i.e.
you can't talk to the network)?
Do you mean they work but you don't notice any significant performance
difference?
Do you mean the machine halts and catches fire?

Like I said, you don't have to do anything to use the checksum offload
capabilities: they're just on, and that's that. In terms of peformance,
the fact that the chip doesn't do checksums over fragmented packets
means that the biggest improvement will be with packets that fit into
a single frame.

-Bill

--
=============================================================================
-Bill Paul            (510) 749-2329 | Senior Engineer, Master of Unix-Fu
                 wpaul@windriver.com | Wind River Systems
=============================================================================
      "If stupidity were a handicap, you'd have the best parking spot."
=============================================================================

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030227183346.657C937B401>