.\" Copyright (c) 2009 Pyun YongHyeon
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" $FreeBSD$
.\"
.Dd August 9, 2010
.Dt ALC 4
.Os
.Sh NAME
.Nm alc
.Nd Atheros AR813x/AR815x Gigabit/Fast 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 alc"
.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_alc_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
device driver provides support for Atheros AR813x and AR815x PCI
Express Gigabit/Fast Ethernet controllers.
.Pp
All LOMs supported by the
.Nm
driver have TCP/UDP/IP checksum offload for transmit, TCP
segmentation offload (TSO), hardware VLAN tag stripping/insertion
features, Wake On Lan (WOL) and an interrupt moderation mechanism
as well as a 64-bit multicast hash filter.
.Pp
The AR813x and AR815x supports Jumbo Frames (up to 9216 and 6144
bytes, respectively), which can be configured 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.
.Pp
The
.Nm
driver supports the following media types:
.Bl -tag -width ".Cm 10baseT/UTP"
.It Cm autoselect
Enable autoselection of the media type and options.
The user can manually override
the autoselected mode by adding media options to
.Xr rc.conf 5 .
.It Cm 10baseT/UTP
Set 10Mbps operation.
.It Cm 100baseTX
Set 100Mbps (Fast Ethernet) operation.
.It Cm 1000baseTX
Set 1000baseTX operation over twisted pair.
.El
.Pp
The
.Nm
driver supports the following media options:
.Bl -tag -width ".Cm full-duplex"
.It Cm full-duplex
Force full duplex operation.
.It Cm half-duplex
Force half duplex operation.
.El
.Pp
For more information on configuring this device, see
.Xr ifconfig 8 .
.Sh HARDWARE
The
.Nm
device driver provides support for the following Ethernet controllers:
.Pp
.Bl -bullet -compact
.It
Atheros AR8131 PCI Express Gigabit Ethernet controller
.It
Atheros AR8132 PCI Express Fast Ethernet controller
.It
Atheros AR8151 v1.0 PCI Express Gigabit Ethernet controller
.It
Atheros AR8151 v2.0 PCI Express Gigabit Ethernet controller
.It
Atheros AR8152 v1.1 PCI Express Fast Ethernet controller
.It
Atheros AR8152 v2.0 PCI Express Fast Ethernet controller
.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 "xxxxxx"
.It Va hw.alc.msi_disable
This tunable disables MSI support on the Ethernet hardware.
The default value is 0.
.It Va hw.alc.msix_disable
This tunable disables MSI-X support on the Ethernet hardware.
The default value is 0.
.El
.Sh SYSCTL VARIABLES
The following variables are available as both
.Xr sysctl 8
variables and
.Xr loader 8
tunables:
.Bl -tag -width "xxxxxx"
.It Va dev.alc.%d.int_rx_mod
Maximum amount of time to delay receive interrupt processing in
units of 1us.
The accepted range is 0 to 130000, the default is 100(100us).
Value 0 completely disables the interrupt moderation.
.It Va dev.alc.%d.int_tx_mod
Maximum amount of time to delay transmit interrupt processing in
units of 1us.
The accepted range is 0 to 130000, the default is 1000(1ms).
Value 0 completely disables the interrupt moderation.
.It Va dev.alc.%d.process_limit
Maximum amount of Rx frames to be processed in the event loop before
rescheduling a taskqueue.
The accepted range is 32 to 255, the default value is 64 events.
The interface does not need to be brought down and up again before
a change takes effect.
.El
.Sh SEE ALSO
.Xr altq 4 ,
.Xr arp 4 ,
.Xr miibus 4 ,
.Xr netintro 4 ,
.Xr ng_ether 4 ,
.Xr vlan 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
driver was written by
.An Pyun YongHyeon
.Aq yongari@FreeBSD.org .
It first appeared in
.Fx 8.0 .