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).

HARDWARE
The et driver supports Agere ET1310 10/100/Gigabit Ethernet adapters.

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 interrupts 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 recommended 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 moderation. The default value is 1000000000 (nanoseconds).

SEE ALSO
altq(4), arp(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
-nosplit The et driver was written by Sepherosa Ziehau <sepherosa@gmail.com> for DragonFly. It was ported to FreeBSD by Xin LI <delphij@FreeBSD.org>.