NAME

jme — JMicron Technologies JMC250 Gigabit Ethernet and JMC260 Fast Ethernet controller driver

SYNOPSIS

jme* at pci? dev ? function ?

Configuration of PHYs is necessary. See mii(4).

DESCRIPTION

The jme device driver supports network adapters based on the JMicron Technologies JMC250 Gigabit Ethernet and JMC260 Fast Ethernet chips. The following features are supported:

IPv4 transmit/receive IP/TCP/UDP checksum offload 
IPv6 transmit TCP/UDP checksum offload 
IPv4 and IPv6 TCP segmentation offload 
VLAN tag insertion/removal 
Interrupt coalescing 
10/100/1000Mbps operation in full-duplex mode 
10/100Mbps operation in half-duplex mode 
Jumbo frames (up to 9022 bytes)

Due to hardware limitation checksums and TCP segmentation offload can't be enabled if the configured MTU is larger than 4000 bytes.

Interrupt coalescing can be controlled on a per-adapter basis through the following sysctls:

hw.jme.jme<x>.int_rxtos

jme receive interrupt moderation timer, in microseconds (defaults to 100)

hw.jme.jme<x>.int_rxct

jme receive interrupt moderation packet counter (defaults to 128)

hw.jme.jme<x>.int_txto

jme transmit interrupt moderation timer, in microseconds (defaults to 100)

hw.jme.jme<x>.int_txct

jme transmit interrupt moderation packet counter (defaults to 128)

SEE ALSO

ifmedia(4), mii(4), netintro(4), pci(4), ifconfig(8)

HISTORY

The jme device driver first appeared in NetBSD 5.0.

BUGS

Hardware bugs prevent support of IPv6 receive TCP/UDP checksum offload in the JMC250 rev A2, and is disabled in the driver. This should be revisited when a newer hardware revision is available.