ET(4) BSD Kernel Interfaces Manual ET(4)NAME
et — Agere ET1310 10/100/Gigabit Ethernet driver
SYNOPSIS
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
device miibus
device et
Alternatively, to load the driver as a module at boot time, place the
following line in loader.conf(5):
if_et_load="YES"
DESCRIPTION
The et driver supports PCI Express Ethernet adapters based on the Agere
ET1310 chip.
The et driver supports the following media types:
autoselect Enable autoselection of the media types and options. The
user can manually override the autoselected mode by adding
media options to the /etc/rc.conf file.
10baseT/UTP Set 10Mbps operation. The mediaopt option can also be used
to select either full-duplex or half-duplex modes.
100baseTX Set 100Mbps (Fast Ethernet) operation. The mediaopt option
can also be used to select either full-duplex or half-duplex
modes.
1000baseT Set 1000Mbps (Gigabit Ethernet) operation. The mediaopt
option can only be set to full-duplex mode.
The et driver supports the following media options:
full-duplex Force full-duplex operation.
half-duplex Force half-duplex operation.
Note that the 1000baseT media type is only available if it is supported
by the adapter. For more information on configuring this device, see
ifconfig(8).
TUNABLES
hw.et.rx_intr_npkts This value controls how many packets should be
received before a receive interrupt is generated.
The default value is 32. It is recommended to set
this value above 38 to prevent the host from being
livelocked under a high degree of stress.
hw.et.rx_intr_delay This value delays the generation of receive inter‐
rupts in units of ~4 microseconds. It is used
together with hw.et.rx_intr_npkts to achieve RX
interrupt moderation. The default value is 20.
hw.et.tx_intr_nsegs This value controls how many segments (not packets)
should be transmitted before a transmit interrupt is
generated. The default value is 126. It is recom‐
mended to set this value below 280 to prevent the TX
ring from underflowing.
hw.et.timer This value controls how often a timer interrupt
should be generated. It is used together with
hw.et.tx_intr_nsegs to achieve TX interrupt modera‐
tion. The default value is 1000000000 (nanosec‐
onds).
SEE ALSOarp(4), miibus(4), netintro(4), ng_ether(4), vlan(4), ifconfig(8)HISTORY
The et device driver first appeared in DragonFly 1.11. The first FreeBSD
release to include it was FreeBSD 8.0.
AUTHORS
The et driver was written by Sepherosa Ziehau ⟨sepherosa@gmail.com⟩ for
DragonFly. It was ported to FreeBSD by Xin LI ⟨delphij@FreeBSD.org⟩.
BSD July 14, 2008 BSD
