xref: /freebsd/share/man/man4/cdce.4 (revision 5b9c547c)
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28.\" $NetBSD: cdce.4,v 1.4 2004/12/08 18:35:56 peter Exp $
29.\" $FreeBSD$
30.\"
31.Dd September 25, 2014
32.Dt CDCE 4
33.Os
34.Sh NAME
35.Nm cdce
36.Nd "USB Communication Device Class Ethernet driver"
37.Sh SYNOPSIS
38To compile this driver into the kernel,
39place the following lines in your
40kernel configuration file:
41.Bd -ragged -offset indent
42.Cd "device uhci"
43.Cd "device ohci"
44.Cd "device usb"
45.Cd "device cdce"
46.Ed
47.Pp
48Alternatively, to load the driver as a
49module at boot time, place the following line in
50.Xr loader.conf 5 :
51.Bd -literal -offset indent
52if_cdce_load="YES"
53.Ed
54.Sh DESCRIPTION
55The
56.Nm
57driver provides support for USB Host-to-Host (aka USB-to-USB) and
58USB-to-Ethernet bridges based on the USB Communication Device Class
59(CDC) and Ethernet subclass.
60.Pp
61The USB bridge appears as a regular network interface on both sides,
62transporting Ethernet frames.
63.Pp
64For more information on configuring this device, see
65.Xr ifconfig 8 .
66.Pp
67USB 1.x bridges support speeds of up to 12Mbps, and USB 2.0 speeds of
68up to 480Mbps.
69.Pp
70Packets are
71received and transmitted over separate USB bulk transfer endpoints.
72.Pp
73The
74.Nm
75driver does not support different media types or options.
76.Sh HARDWARE
77The following devices are supported by the
78.Nm
79driver:
80.Pp
81.Bl -bullet -compact
82.It
83Prolific PL-2501 Host-to-Host Bridge Controller
84.It
85Sharp Zaurus PDA
86.It
87Terayon TJ-715 DOCSIS Cable Modem
88.El
89.Sh DIAGNOSTICS
90.Bl -diag
91.It "cdce%d: no union descriptor"
92The driver could not fetch an interface descriptor from the USB
93device.
94For a manually added USB vendor/product, the CDCE_NO_UNION flag
95can be tried to work around the missing descriptor.
96.It "cdce%d: no data interface"
97.It "cdce%d: could not read endpoint descriptor"
98.It "cdce%d: unexpected endpoint"
99.It "cdce%d: could not find data bulk in/out"
100For a manually added USB vendor/product, these errors indicate
101that the bridge is not compatible with the driver.
102.It "cdce%d: watchdog timeout"
103A packet was queued for transmission and a transmit command was
104issued, however the device failed to acknowledge the transmission
105before a timeout expired.
106.It "cdce%d: no memory for rx list -- packet dropped!"
107Memory allocation through MGETHDR or MCLGET failed, the system
108is running low on mbufs.
109.It "cdce%d: abort/close rx/tx pipe failed"
110.It "cdce%d: rx/tx list init failed"
111.It "cdce%d: open rx/tx pipe failed"
112.It "cdce%d: usb error on rx/tx"
113.El
114.Sh SEE ALSO
115.Xr arp 4 ,
116.Xr intro 4 ,
117.Xr ipheth 4 ,
118.Xr netintro 4 ,
119.Xr urndis 4 ,
120.Xr usb 4 ,
121.Xr ifconfig 8
122.Rs
123.%T "Universal Serial Bus Class Definitions for Communication Devices"
124.%U http://www.usb.org/developers/devclass_docs/usbcdc11.pdf
125.Re
126.Rs
127.%T "Data sheet Prolific PL-2501 Host-to-Host Bridge/Network Controller"
128.%U http://tech.prolific.com.tw/visitor/fcabdl.asp?fid=20679530
129.Re
130.Sh HISTORY
131The
132.Nm
133device driver first appeared in
134.Ox 3.6 ,
135.Nx 3.0
136and
137.Fx 6.0 .
138.Sh AUTHORS
139.An -nosplit
140The
141.Nm
142driver was written by
143.An Craig Boston Aq Mt craig@tobuj.gank.org
144based on the
145.Xr aue 4
146driver written by
147.An Bill Paul Aq Mt wpaul@windriver.com
148and ported to
149.Ox
150by
151.An Daniel Hartmeier Aq Mt dhartmei@openbsd.org .
152.Sh CAVEATS
153Many USB devices notoriously fail to report their class and interfaces
154correctly.
155Undetected products might work flawlessly when their vendor and product IDs
156are added to the driver manually.
157