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.\" $FreeBSD: src/share/man/man4/em.4,v 1.30 2008/10/06 21:55:53 simon Exp $
.\" $DragonFly: src/share/man/man4/em.4,v 1.12 2008/07/11 10:38:50 thomas Exp $
.\"
.Dd February 27, 2009
.Dt EM 4
.Os
.Sh NAME
.Nm em
.Nd "Intel(R) PRO/1000 Gigabit Ethernet adapter 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 ig_hal"
.Cd "device em"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following lines in
.Xr loader.conf 5 :
.Bd -literal -offset indent
ig_hal_load="YES"
if_em_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for PCI Gigabit Ethernet adapters based on
the Intel 82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546,
82546EB, 82546GB, 82547, 82571, 81572, 82573, and 82574 Ethernet
controller chips.
The driver supports Transmit/Receive checksum offload
and Jumbo Frames on all but 82542-based adapters.
.\" Furthermore it supports TCP segmentation offload (TSO) on all adapters but
.\" those based on the 82543, 82544 and 82547 controller chips.
For further hardware information, see the
.Pa README
included with the driver.
.Pp
For questions related to hardware requirements,
refer to the documentation supplied with your Intel PRO/1000 adapter.
All hardware requirements listed apply to use with
.Dx .
.Pp
Support for Jumbo Frames is provided via the interface MTU setting.
Selecting an MTU larger than 1500 bytes with the
.Xr ifconfig 8
utility configures the adapter to receive and transmit Jumbo Frames.
The maximum MTU size for Jumbo Frames is 16114.
.Pp
This driver version supports VLANs.
The
.Nm
driver supports the following media types:
.Bl -tag -width ".Cm 10baseT/UTP"
.It Cm autoselect
Enables auto-negotiation for speed and duplex.
.It Cm 10baseT/UTP
Sets 10Mbps operation.
Use the
.Cm mediaopt
option to select
.Cm full-duplex
mode.
.It Cm 100baseTX
Sets 100Mbps operation.
Use the
.Cm mediaopt
option to select
.Cm full-duplex
mode.
.It Cm 1000baseSX
Sets 1000Mbps operation.
Only
.Cm full-duplex
mode is supported at this speed.
.It Cm 1000baseT
Sets 1000Mbps operation.
Only
.Cm full-duplex
mode is supported at this speed.
.El
.Pp
The
.Nm
driver supports the following media options:
.Bl -tag -width ".Cm full-duplex"
.It Cm full-duplex
Forces full-duplex operation
.It Cm half-duplex
Forces half-duplex operation.
.El
.Pp
Only use
.Cm mediaopt
to set the driver to
.Cm full-duplex .
If
.Cm mediaopt
is not specified, the driver defaults to
.Cm half-duplex .
.Pp
For more information on configuring this device, see
.Xr ifconfig 8 .
The
.Nm
driver supports
.Xr polling 4 .
.Sh HARDWARE
The
.Nm
driver supports Gigabit Ethernet adapters based on the Intel
82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546, 82546EB,
82546GB, 82547, 82571, 82572, 82573, and 82574 controller chips:
.Pp
.Bl -bullet -compact
.It
Intel PRO/1000 CT Network Connection (82547)
.It
Intel PRO/1000 F Server Adapter (82543)
.It
Intel PRO/1000 Gigabit Server Adapter (82542)
.It
Intel PRO/1000 GT Desktop Adapter (82541PI)
.It
Intel PRO/1000 MF Dual Port Server Adapter (82546)
.It
Intel PRO/1000 MF Server Adapter (82545)
.It
Intel PRO/1000 MF Server Adapter (LX) (82545)
.It
Intel PRO/1000 MT Desktop Adapter (82540)
.It
Intel PRO/1000 MT Desktop Adapter (82541)
.It
Intel PRO/1000 MT Dual Port Server Adapter (82546)
.It
Intel PRO/1000 MT Quad Port Server Adapter (82546EB)
.It
Intel PRO/1000 MT Server Adapter (82545)
.It
Intel PRO/1000 PF Dual Port Server Adapter (82571)
.It
Intel PRO/1000 PF Quad Port Server Adapter (82571)
.It
Intel PRO/1000 PF Server Adapter (82572)
.It
Intel PRO/1000 PT Desktop Adapter (82572)
.It
Intel PRO/1000 PT Dual Port Server Adapter (82571)
.It
Intel PRO/1000 PT Quad Port Server Adapter (82571)
.It
Intel PRO/1000 PT Server Adapter (82572)
.It
Intel PRO/1000 T Desktop Adapter (82544)
.It
Intel PRO/1000 T Server Adapter (82543)
.It
Intel PRO/1000 XF Server Adapter (82544)
.It
Intel PRO/1000 XT Server Adapter (82544)
.El
.Sh LOADER TUNABLES
Tunables can be set at the
.Xr loader 8
prompt before booting the kernel or stored in
.Xr loader.conf 5 .
.Bl -tag -width indent
.It Va hw.em.int_throttle_ceil
Hardware interrupt throttling rate.
The default value is 10000Hz.
.It Va hw.em.rxd
Number of receive descriptors allocated by the driver.
The default value is 256.
The 82542 and 82543-based adapters can handle up to 256 descriptors,
while others can have up to 4096.
.It Va hw.em.txd
Number of transmit descriptors allocated by the driver.
The default value is 256.
The 82542 and 82543-based adapters can handle up to 256 descriptors,
while others can have up to 4096.
.It Va hw.em.int_tx_nsegs
This value controls how many transmit descriptors should be consumed
by the hardware before the hardware generates a transmit interrupt.
The default value is 1/16 of the number of transmit descriptors.
If
.Xr polling 4
is not used on the hardware and
the major part of the transmitted data are bulk data,
this value could safely be set to 1/2 of the number of transmit descriptors.
.El
.Sh DIAGNOSTICS
.Bl -diag
.It "em%d: Unable to allocate bus resource: memory"
A fatal initialization error has occurred.
.It "em%d: Unable to allocate bus resource: interrupt"
A fatal initialization error has occurred.
.It "em%d: watchdog timeout -- resetting"
The device has stopped responding to the network, or there is a problem with
the network connection (cable).
.El
.Sh SUPPORT
For general information and support,
go to the Intel support website at:
.Pa http://support.intel.com .
.Pp
If an issue is identified with the released source code on the supported kernel
with a supported adapter, email the specific information related to the
issue to
.Aq freebsdnic@mailbox.intel.com .
.Sh SEE ALSO
.Xr arp 4 ,
.Xr ifmedia 4 ,
.Xr netintro 4 ,
.Xr ng_ether 4 ,
.Xr polling 4 ,
.Xr vlan 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
device driver first appeared in
.Fx 4.4 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Intel Corporation Aq freebsdnic@mailbox.intel.com .