cdce (4)

Leading comments

Copyright (c) 2004 Daniel Hartmeier
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

   - Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
   - Redistributions in binary form must reproduce the above
     copyright notice, this list of conditions and the following
     disclaimer in the documentati...

(The comments found at the beginning of the groff file "man4/cdce.4freebsd".)

NAME

cdce - USB Communication Device Class Ethernet driver

SYNOPSIS

To compile this driver into the kernel, place the following lines in your kernel configuration file:

device uhci device ohci device usb device cdce

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf5:

if_cdce_load="YES"

DESCRIPTION

The driver provides support for USB Host-to-Host (aka USB-to-USB) and USB-to-Ethernet bridges based on the USB Communication Device Class (CDC) and Ethernet subclass.

The USB bridge appears as a regular network interface on both sides, transporting Ethernet frames.

For more information on configuring this device, see ifconfig(8).

USB 1.x bridges support speeds of up to 12Mbps, and USB 2.0 speeds of up to 480Mbps.

Packets are received and transmitted over separate USB bulk transfer endpoints.

The driver does not support different media types or options.

HARDWARE

The following devices are supported by the driver:

• Prolific PL-2501 Host-to-Host Bridge Controller
• Sharp Zaurus PDA
• Terayon TJ-715 DOCSIS Cable Modem

DIAGNOSTICS

"cdce%d: no union descriptor"

The driver could not fetch an interface descriptor from the USB device. For a manually added USB vendor/product, the CDCE_NO_UNION flag can be tried to work around the missing descriptor.

"cdce%d: no data interface"

"cdce%d: could not read endpoint descriptor"

"cdce%d: unexpected endpoint"

"cdce%d: could not find data bulk in/out"

For a manually added USB vendor/product, these errors indicate that the bridge is not compatible with the driver.

"cdce%d: watchdog timeout"

A packet was queued for transmission and a transmit command was issued, however the device failed to acknowledge the transmission before a timeout expired.

"cdce%d: no memory for rx list -- packet dropped!"

Memory allocation through MGETHDR or MCLGET failed, the system is running low on mbufs.

"cdce%d: abort/close rx/tx pipe failed"

"cdce%d: rx/tx list init failed"

"cdce%d: open rx/tx pipe failed"

"cdce%d: usb error on rx/tx"

SEE ALSO

arp(4), intro(4), netintro(4), usb(4), ifconfig(8)

"Universal Serial Bus Class Definitions for Communication Devices"

"Data sheet Prolific PL-2501 Host-to-Host Bridge/Network Controller"

HISTORY

The device driver first appeared in Ox 3.6 , Nx 3.0 and Fx 6.0 .

AUTHORS

An -nosplit The driver was written by An Craig Boston Aq craig@tobuj.gank.org based on the aue(4) driver written by An Bill Paul Aq wpaul@windriver.com and ported to Ox by An Daniel Hartmeier Aq dhartmei@openbsd.org .

CAVEATS

Many USB devices notoriously fail to report their class and interfaces correctly. Undetected products might work flawlessly when their vendor and product IDs are added to the driver manually.