JME(4) BSD Kernel Interfaces Manual JME(4)NAMEjme — JMicron Gigabit/Fast Ethernet driver
SYNOPSIS
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
device miibus
device jme
Alternatively, to load the driver as a module at boot time, place the
following line in loader.conf(5):
if_jme_load="YES"
DESCRIPTION
The jme device driver provides support for JMicron JMC250 PCI Express
Gigabit Ethernet controllers and JMicron JMC260 PCI Express Fast Ethernet
controllers.
All LOMs supported by the jme driver have TCP/UDP/IP checksum offload for
both transmit and receive, hardware VLAN tag stripping/insertion fea‐
tures, an interrupt coalescing/moderation mechanism as well as a 64-bit
multicast hash filter.
The JMC250 also supports Jumbo Frames (up to 9216 bytes), which can be
configured via the interface MTU setting. Selecting an MTU larger than
1500 bytes with the ifconfig(8) utility configures the adapter to receive
and transmit Jumbo Frames.
The jme driver supports the following media types:
autoselect Enable autoselection of the media type and options. The
user can manually override the autoselected mode by adding
media options to rc.conf(5).
10baseT/UTP Set 10Mbps operation.
100baseTX Set 100Mbps (Fast Ethernet) operation.
1000baseT Set 1000baseT operation over twisted pair.
The jme driver supports the following media options:
full-duplex Force full duplex operation.
half-duplex Force half duplex operation.
For more information on configuring this device, see ifconfig(8). The
jme driver supports polling(4).
MIB Variables
A number of per-interface variables are implemented in the hw.jmeX branch
of the sysctl(3) MIB.
tx_coal_to Maximum amount of time to delay for TX completion inter‐
rupt in units of 1us. The accepted range is 1 to 65535,
the default is 65535 (65535us).
tx_coal_pkt Maximum number of packets to fire TX completion interrupt.
The accepted range is 0 to 255, the default is 64. Packet
count based TX interrupt coalescing could be disabled by
setting this variable to 0.
rx_coal_to Maximum amount of time to delay for RX completion inter‐
rupt in units of 1us. The accepted range is 1 to 65535,
the default is 100 (100us).
rx_coal_pkt Maximum number of packets to fire RX completion interrupt.
The accepted range is 0 to 255, the default is 64. Packet
count based RX interrupt coalescing could be disabled by
setting this variable to 0.
rx_desc_count Number of RX descriptors per-ring (read-only). Use the
tunable hw.jme.rx_desc_count to configure it.
tx_desc_count Number of TX descriptors (read-only). Use the tunable
hw.jme.tx_desc_count to configure it.
rx_ring_count Number of RX rings (read-only). Use the tunable
hw.jme.rx_ring_count to configure it.
rx_ring_inuse Number of RX rings being used (read-only).
SEE ALSOaltq(4), arp(4), ifmedia(4), miibus(4), netintro(4), ng_ether(4),
polling(4), vlan(4), ifconfig(8)HISTORY
The jme driver was written by Pyun YongHyeon ⟨yongari@FreeBSD.org⟩. It
first appeared in FreeBSD 7.1 and was imported into DragonFly 2.1.
BSD July 26, 2008 BSD
