1.\" $NetBSD: ec.4,v 1.9 2002/02/13 08:17:33 ross Exp $ 2.\" 3.\" Copyright (c) 1997 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 8.\" NASA Ames Research Center. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. All advertising materials mentioning features or use of this software 19.\" must display the following acknowledgement: 20.\" This product includes software developed by the NetBSD 21.\" Foundation, Inc. and its contributors. 22.\" 4. Neither the name of The NetBSD Foundation nor the names of its 23.\" contributors may be used to endorse or promote products derived 24.\" from this software without specific prior written permission. 25.\" 26.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36.\" POSSIBILITY OF SUCH DAMAGE. 37.\" 38.Dd October 20, 1997 39.Dt EC 4 40.Os 41.Sh NAME 42.Nm ec 43.Nd driver for 3Com Etherlink II (3c503) 44.Tn ISA 45bus 46.Tn Ethernet 47cards 48.Sh SYNOPSIS 49.Cd "ec0 at isa? port 0x250 iomem 0xd8000 irq 9" 50.Sh DESCRIPTION 51The 52.Nm 53device driver supports 3Com Etherlink II (3c503) 54.Tn Ethernet 55cards for 56.Tn ISA 57bus which are based on the National Semiconductor DP8390/WD83C690 58.Tn Ethernet 59interface chips. 60.Sh MEDIA SELECTION 61The Etherlink II supports two media types on a single card. 62All support the 63.Tn AUI 64media type. 65The other media is either 66.Tn BNC 67or 68.Tn UTP 69behind a transceiver. 70Software cannot differentiate between 71.Tn BNC 72and 73.Tn UTP 74cards. 75.Pp 76To enable the AUI media, select the 77.Em 10base5 78or 79.Em aui 80media type with 81.Xr ifconfig 8 's 82.Sq media 83directive. 84To select the other media 85.Po 86.Tn BNC 87or 88.Tn UTP 89.Pc , 90select the 91.Em 10base2 92or 93.Em bnc 94media type. 95.Sh DIAGNOSTICS 96.Bl -diag 97.It "ec0: wildcarded IRQ is not allowed" 98.Pp 99The 100.Tn IRQ 101was wildcarded in the kernel configuration file. 102This is not supported. 103.It "ec0: invalid IRQ \*[Lt]n\*[Gt], must be 3, 4, 5, or 9" 104.Pp 105An 106.Tn IRQ 107other than the above 108.Tn IRQ 109values was specified in the kernel configuration file. 110The Etherlink II hardware only supports the above listed 111.Tn IRQ 112values. 113.It "ec0: failed to clear shared memory at offset \*[Lt]off\*[Gt]" 114.Pp 115The memory test was unable to clear shared the interface's shared memory 116region. 117This often indicates that the card is configured at a conflicting 118.Em iomem 119address. 120.It "ec0: warning - receiver ring buffer overrun" 121.Pp 122The DP8390 123.Tn Ethernet 124chip used by this board implements a shared-memory 125ring-buffer to store incoming packets. 126The 3c503 usually has only 8K bytes of shared memory. 127This is only enough room for about 4 full-size (1500 byte) packets. 128This can sometimes be a problem, especially on the original 3c503, because 129these boards' shared-memory access speed is quite slow; typically only 130about 1MB/second. 131The overhead of this slow memory access, and the fact that there 132is only room for 4 full-sized packets means that the ring-buffer 133will occasionally overrun. 134.Pp 135When an overrun occurs, the board must be reset to avoid a lockup 136problem in early revision DP8390 137.Tn Ethernet 138chips. 139Resetting the board causes all of the data in the ring-buffer to be 140lost, requiring the data to be retransmitted/received, congesting the board 141further. 142Because of this, maximum throughput on these boards is only about 143400-600K bytes per second. 144.Pp 145This problem is exacerbated by 146.Tn NFS 147because the 8-bit boards lack sufficient packet buffer memory to 148support the default 8K byte packets that 149.Tn NFS 150and other protocols use as their default. 151If these cards must be used 152with 153.Tn NFS , 154use the 155.Xr mount_nfs 8 156.Fl \&r 157and 158.Fl \&w 159options in 160.Pa /etc/fstab 161to limit NFS's packet size. 1624K (4096) byte packets generally work. 163.El 164.Sh SEE ALSO 165.Xr ifmedia 4 , 166.Xr intro 4 , 167.Xr isa 4 , 168.Xr ifconfig 8 , 169.Xr mount_nfs 8 170