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

     The et driver was written by Sepherosa Ziehau <sepherosa@gmail.com> for DragonFly.  It was
     ported to FreeBSD by Xin LI <delphij@FreeBSD.org>.