1.. SPDX-License-Identifier: GPL-2.0 2 3============================================================================= 4Linux and the 3Com EtherLink III Series Ethercards (driver v1.18c and higher) 5============================================================================= 6 7This file contains the instructions and caveats for v1.18c and higher versions 8of the 3c509 driver. You should not use the driver without reading this file. 9 10release 1.0 11 1228 February 2002 13 14Current maintainer (corrections to): 15 David Ruggiero <jdr@farfalle.com> 16 17Introduction 18============ 19 20The following are notes and information on using the 3Com EtherLink III series 21ethercards in Linux. These cards are commonly known by the most widely-used 22card's 3Com model number, 3c509. They are all 10mb/s ISA-bus cards and shouldn't 23be (but sometimes are) confused with the similarly-numbered PCI-bus "3c905" 24(aka "Vortex" or "Boomerang") series. Kernel support for the 3c509 family is 25provided by the module 3c509.c, which has code to support all of the following 26models: 27 28 - 3c509 (original ISA card) 29 - 3c509B (later revision of the ISA card; supports full-duplex) 30 - 3c589 (PCMCIA) 31 - 3c589B (later revision of the 3c589; supports full-duplex) 32 - 3c579 (EISA) 33 34Large portions of this documentation were heavily borrowed from the guide 35written the original author of the 3c509 driver, Donald Becker. The master 36copy of that document, which contains notes on older versions of the driver, 37currently resides on Scyld web server: http://www.scyld.com/. 38 39 40Special Driver Features 41======================= 42 43Overriding card settings 44 45The driver allows boot- or load-time overriding of the card's detected IOADDR, 46IRQ, and transceiver settings, although this capability shouldn't generally be 47needed except to enable full-duplex mode (see below). An example of the syntax 48for LILO parameters for doing this:: 49 50 ether=10,0x310,3,0x3c509,eth0 51 52This configures the first found 3c509 card for IRQ 10, base I/O 0x310, and 53transceiver type 3 (10base2). The flag "0x3c509" must be set to avoid conflicts 54with other card types when overriding the I/O address. When the driver is 55loaded as a module, only the IRQ may be overridden. For example, 56setting two cards to IRQ10 and IRQ11 is done by using the irq module 57option:: 58 59 options 3c509 irq=10,11 60 61 62Full-duplex mode 63================ 64 65The v1.18c driver added support for the 3c509B's full-duplex capabilities. 66In order to enable and successfully use full-duplex mode, three conditions 67must be met: 68 69(a) You must have a Etherlink III card model whose hardware supports full- 70duplex operations. Currently, the only members of the 3c509 family that are 71positively known to support full-duplex are the 3c509B (ISA bus) and 3c589B 72(PCMCIA) cards. Cards without the "B" model designation do *not* support 73full-duplex mode; these include the original 3c509 (no "B"), the original 743c589, the 3c529 (MCA bus), and the 3c579 (EISA bus). 75 76(b) You must be using your card's 10baseT transceiver (i.e., the RJ-45 77connector), not its AUI (thick-net) or 10base2 (thin-net/coax) interfaces. 78AUI and 10base2 network cabling is physically incapable of full-duplex 79operation. 80 81(c) Most importantly, your 3c509B must be connected to a link partner that is 82itself full-duplex capable. This is almost certainly one of two things: a full- 83duplex-capable Ethernet switch (*not* a hub), or a full-duplex-capable NIC on 84another system that's connected directly to the 3c509B via a crossover cable. 85 86Full-duplex mode can be enabled using 'ethtool'. 87 88.. warning:: 89 90 Extremely important caution concerning full-duplex mode 91 92 Understand that the 3c509B's hardware's full-duplex support is much more 93 limited than that provide by more modern network interface cards. Although 94 at the physical layer of the network it fully supports full-duplex operation, 95 the card was designed before the current Ethernet auto-negotiation (N-way) 96 spec was written. This means that the 3c509B family ***cannot and will not 97 auto-negotiate a full-duplex connection with its link partner under any 98 circumstances, no matter how it is initialized***. If the full-duplex mode 99 of the 3c509B is enabled, its link partner will very likely need to be 100 independently _forced_ into full-duplex mode as well; otherwise various nasty 101 failures will occur - at the very least, you'll see massive numbers of packet 102 collisions. This is one of very rare circumstances where disabling auto- 103 negotiation and forcing the duplex mode of a network interface card or switch 104 would ever be necessary or desirable. 105 106 107Available Transceiver Types 108=========================== 109 110For versions of the driver v1.18c and above, the available transceiver types are: 111 112== ========================================================================= 1130 transceiver type from EEPROM config (normally 10baseT); force half-duplex 1141 AUI (thick-net / DB15 connector) 1152 (undefined) 1163 10base2 (thin-net == coax / BNC connector) 1174 10baseT (RJ-45 connector); force half-duplex mode 1188 transceiver type and duplex mode taken from card's EEPROM config settings 11912 10baseT (RJ-45 connector); force full-duplex mode 120== ========================================================================= 121 122Prior to driver version 1.18c, only transceiver codes 0-4 were supported. Note 123that the new transceiver codes 8 and 12 are the *only* ones that will enable 124full-duplex mode, no matter what the card's detected EEPROM settings might be. 125This insured that merely upgrading the driver from an earlier version would 126never automatically enable full-duplex mode in an existing installation; 127it must always be explicitly enabled via one of these code in order to be 128activated. 129 130The transceiver type can be changed using 'ethtool'. 131 132 133Interpretation of error messages and common problems 134---------------------------------------------------- 135 136Error Messages 137^^^^^^^^^^^^^^ 138 139eth0: Infinite loop in interrupt, status 2011. 140These are "mostly harmless" message indicating that the driver had too much 141work during that interrupt cycle. With a status of 0x2011 you are receiving 142packets faster than they can be removed from the card. This should be rare 143or impossible in normal operation. Possible causes of this error report are: 144 145 - a "green" mode enabled that slows the processor down when there is no 146 keyboard activity. 147 148 - some other device or device driver hogging the bus or disabling interrupts. 149 Check /proc/interrupts for excessive interrupt counts. The timer tick 150 interrupt should always be incrementing faster than the others. 151 152No received packets 153^^^^^^^^^^^^^^^^^^^ 154 155If a 3c509, 3c562 or 3c589 can successfully transmit packets, but never 156receives packets (as reported by /proc/net/dev or 'ifconfig') you likely 157have an interrupt line problem. Check /proc/interrupts to verify that the 158card is actually generating interrupts. If the interrupt count is not 159increasing you likely have a physical conflict with two devices trying to 160use the same ISA IRQ line. The common conflict is with a sound card on IRQ10 161or IRQ5, and the easiest solution is to move the 3c509 to a different 162interrupt line. If the device is receiving packets but 'ping' doesn't work, 163you have a routing problem. 164 165Tx Carrier Errors Reported in /proc/net/dev 166^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 167 168 169If an EtherLink III appears to transmit packets, but the "Tx carrier errors" 170field in /proc/net/dev increments as quickly as the Tx packet count, you 171likely have an unterminated network or the incorrect media transceiver selected. 172 1733c509B card is not detected on machines with an ISA PnP BIOS. 174^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 175 176While the updated driver works with most PnP BIOS programs, it does not work 177with all. This can be fixed by disabling PnP support using the 3Com-supplied 178setup program. 179 1803c509 card is not detected on overclocked machines 181^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 182 183Increase the delay time in id_read_eeprom() from the current value, 500, 184to an absurdly high value, such as 5000. 185 186 187Decoding Status and Error Messages 188---------------------------------- 189 190 191The bits in the main status register are: 192 193===== ====================================== 194value description 195===== ====================================== 1960x01 Interrupt latch 1970x02 Tx overrun, or Rx underrun 1980x04 Tx complete 1990x08 Tx FIFO room available 2000x10 A complete Rx packet has arrived 2010x20 A Rx packet has started to arrive 2020x40 The driver has requested an interrupt 2030x80 Statistics counter nearly full 204===== ====================================== 205 206The bits in the transmit (Tx) status word are: 207 208===== ============================================ 209value description 210===== ============================================ 2110x02 Out-of-window collision. 2120x04 Status stack overflow (normally impossible). 2130x08 16 collisions. 2140x10 Tx underrun (not enough PCI bus bandwidth). 2150x20 Tx jabber. 2160x40 Tx interrupt requested. 2170x80 Status is valid (this should always be set). 218===== ============================================ 219 220 221When a transmit error occurs the driver produces a status message such as:: 222 223 eth0: Transmit error, Tx status register 82 224 225The two values typically seen here are: 226 2270x82 228^^^^ 229 230Out of window collision. This typically occurs when some other Ethernet 231host is incorrectly set to full duplex on a half duplex network. 232 2330x88 234^^^^ 235 23616 collisions. This typically occurs when the network is exceptionally busy 237or when another host doesn't correctly back off after a collision. If this 238error is mixed with 0x82 errors it is the result of a host incorrectly set 239to full duplex (see above). 240 241Both of these errors are the result of network problems that should be 242corrected. They do not represent driver malfunction. 243 244 245Revision history (this file) 246============================ 247 24828Feb02 v1.0 DR New; major portions based on Becker original 3c509 docs 249 250