.\"	$OpenBSD: nfe.4,v 1.10 2006/08/30 22:56:05 jmc Exp $
.\"	$DragonFly: src/share/man/man4/nfe.4,v 1.10 2008/07/26 07:41:45 sephe Exp $
.\"
.\" Copyright (c) 2006 Jonathan Gray <jsg@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd July 12, 2008
.Dt NFE 4
.Os
.Sh NAME
.Nm nfe
.Nd NVIDIA nForce MCP 10/100/Gigabit Ethernet driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device miibus"
.Cd "device nfe"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
if_nfe_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver supports PCI Ethernet adapters based on the NVIDIA
nForce Media and Communications Processors (MCP), such as
the nForce, nForce 2, nForce 3, CK804, MCP04, MCP51, MCP55,
MCP61, MCP65, MCP67, MCP73, MCP77 and MCP79 Ethernet controller chips.
.Pp
The
.Nm
driver supports the following
.Ar media
types:
.Pp
.Bl -tag -width autoselect -compact
.It Cm autoselect
Enable autoselection of the media type and options.
.It Cm 10baseT
Set 10Mbps operation.
.It Cm 100baseTX
Set 100Mbps (Fast Ethernet) operation.
.It Cm 1000baseT
Set 1000Mbps (Gigabit Ethernet) operation (recent models only).
.El
.Ss MIB Variables and Loader Tunables
The following per-interface variables are implemented in the
.Va hw.nfe Ns Em X
branch of the
.Xr sysctl 3
MIB.
Loader tunables with the same names, but using the prefix
.Va hw.nfe
are also implemented, they apply to all
.Nm
interfaces in system and can be set in
.Xr loader.conf 5 .
.Bl -tag -width ".Va rx_ring_count"
.It Va imtimer
Interrupt moderation time (unit: microseconds).
The default value is -125.
A value of 0 means disabled.
A negative value, -Y, means hardware timer simulated interrupt moderation,
the simulated interrupt moderation timer will be set to Y.
A positive valye, Y, means hardware timer only interrupt moderation,
hardware timer will be set to Y.
Value can be tuned when the interface is running.
Positive values in the range 64-128 seems to be a reasonable.
.It Va rx_ring_count
RX ring count.
sysctl node is read-only.
The default value is 128.
With heavier interrupt moderation (eg. imtimer=-250),
it is recommended to increase rx_ring_count (eg. to 512).
.It Va tx_ring_count
TX ring count.
sysctl node is read-only.
The default value is 256.
.El
.Pp
For more information on configuring this device, see
.Xr ifconfig 8 .
The
.Nm
driver supports
.Xr polling 4 .
.Sh SEE ALSO
.Xr arp 4 ,
.Xr ifmedia 4 ,
.Xr intro 4 ,
.Xr miibus 4 ,
.Xr netintro 4 ,
.Xr pci 4 ,
.Xr polling 4 ,
.Xr vlan 4 ,
.Xr loader.conf 5 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
device driver first appeared in
.Ox 3.9
and was imported into
.Dx 1.7 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Jonathan Gray
.Aq jsg@openbsd.org
and
.An Damien Bergamini
.Aq damien@openbsd.org .
It was ported to
.Dx
by
.An Sepherosa Ziehau
.Aq sepherosa@gmail.com .
.Sh CAVEATS
NVIDIA refuse to release any documentation on their products.