Copyright (c) 2008 Manuel Bouyer
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.Dd October 30, 2019 .Dt JME 4 .Os .Sh NAME .Nm jme .Nd JMicron Technologies JMC250 Gigabit Ethernet and JMC260 Fast Ethernet controller driver .Sh SYNOPSIS .Cd "jme* at pci? dev ? function ?"
p Configuration of PHYs is necessary. See .Xr mii 4 . .Sh DESCRIPTION The .Nm jme device driver supports network adapters based on the JMicron Technologies JMC250 Gigabit Ethernet and JMC260 Fast Ethernet chips. The following features are supported: d -literal -offset indent 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) .Ed
p Due to hardware limitation checksums and TCP segmentation offload can't be enabled if the configured MTU is larger than 4000 bytes.
p Interrupt coalescing can be controlled on a per-adapter basis through the following sysctls: l -tag -width ".Cm hw.jme.jmeXxX.int_rxtos" t Cm hw.jme.jme<x>.int_rxtos jme receive interrupt moderation timer, in microseconds (defaults to 100) t Cm hw.jme.jme<x>.int_rxct jme receive interrupt moderation packet counter (defaults to 128) t Cm hw.jme.jme<x>.int_txto jme transmit interrupt moderation timer, in microseconds (defaults to 100) t Cm hw.jme.jme<x>.int_txct jme transmit interrupt moderation packet counter (defaults to 128) .El .Sh SEE ALSO .Xr ifmedia 4 , .Xr jmphy 4 , .Xr mii 4 , .Xr netintro 4 , .Xr pci 4 , .Xr ifconfig 8 .Sh HISTORY The .Nm device driver first appeared in .Nx 5.0 . .Sh 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.
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