| Linux and the 3Com EtherLink III Series Ethercards (driver v1.18c and higher) | |
| ---------------------------------------------------------------------------- | |
| This file contains the instructions and caveats for v1.18c and higher versions | |
| of the 3c509 driver. You should not use the driver without reading this file. | |
| release 1.0 | |
| 28 February 2002 | |
| Current maintainer (corrections to): | |
| David Ruggiero <jdr@farfalle.com> | |
| ---------------------------------------------------------------------------- | |
| (0) Introduction | |
| The following are notes and information on using the 3Com EtherLink III series | |
| ethercards in Linux. These cards are commonly known by the most widely-used | |
| card's 3Com model number, 3c509. They are all 10mb/s ISA-bus cards and shouldn't | |
| be (but sometimes are) confused with the similarly-numbered PCI-bus "3c905" | |
| (aka "Vortex" or "Boomerang") series. Kernel support for the 3c509 family is | |
| provided by the module 3c509.c, which has code to support all of the following | |
| models: | |
| 3c509 (original ISA card) | |
| 3c509B (later revision of the ISA card; supports full-duplex) | |
| 3c589 (PCMCIA) | |
| 3c589B (later revision of the 3c589; supports full-duplex) | |
| 3c529 (MCA) | |
| 3c579 (EISA) | |
| Large portions of this documentation were heavily borrowed from the guide | |
| written the original author of the 3c509 driver, Donald Becker. The master | |
| copy of that document, which contains notes on older versions of the driver, | |
| currently resides on Scyld web server: http://www.scyld.com/network/3c509.html. | |
| (1) Special Driver Features | |
| Overriding card settings | |
| The driver allows boot- or load-time overriding of the card's detected IOADDR, | |
| IRQ, and transceiver settings, although this capability shouldn't generally be | |
| needed except to enable full-duplex mode (see below). An example of the syntax | |
| for LILO parameters for doing this: | |
| ether=10,0x310,3,0x3c509,eth0 | |
| This configures the first found 3c509 card for IRQ 10, base I/O 0x310, and | |
| transceiver type 3 (10base2). The flag "0x3c509" must be set to avoid conflicts | |
| with other card types when overriding the I/O address. When the driver is | |
| loaded as a module, only the IRQ and transceiver setting may be overridden. | |
| For example, setting two cards to 10base2/IRQ10 and AUI/IRQ11 is done by using | |
| the xcvr and irq module options: | |
| options 3c509 xcvr=3,1 irq=10,11 | |
| (2) Full-duplex mode | |
| The v1.18c driver added support for the 3c509B's full-duplex capabilities. | |
| In order to enable and successfully use full-duplex mode, three conditions | |
| must be met: | |
| (a) You must have a Etherlink III card model whose hardware supports full- | |
| duplex operations. Currently, the only members of the 3c509 family that are | |
| positively known to support full-duplex are the 3c509B (ISA bus) and 3c589B | |
| (PCMCIA) cards. Cards without the "B" model designation do *not* support | |
| full-duplex mode; these include the original 3c509 (no "B"), the original | |
| 3c589, the 3c529 (MCA bus), and the 3c579 (EISA bus). | |
| (b) You must be using your card's 10baseT transceiver (i.e., the RJ-45 | |
| connector), not its AUI (thick-net) or 10base2 (thin-net/coax) interfaces. | |
| AUI and 10base2 network cabling is physically incapable of full-duplex | |
| operation. | |
| (c) Most importantly, your 3c509B must be connected to a link partner that is | |
| itself full-duplex capable. This is almost certainly one of two things: a full- | |
| duplex-capable Ethernet switch (*not* a hub), or a full-duplex-capable NIC on | |
| another system that's connected directly to the 3c509B via a crossover cable. | |
| /////Extremely important caution concerning full-duplex mode///// | |
| Understand that the 3c509B's hardware's full-duplex support is much more | |
| limited than that provide by more modern network interface cards. Although | |
| at the physical layer of the network it fully supports full-duplex operation, | |
| the card was designed before the current Ethernet auto-negotiation (N-way) | |
| spec was written. This means that the 3c509B family ***cannot and will not | |
| auto-negotiate a full-duplex connection with its link partner under any | |
| circumstances, no matter how it is initialized***. If the full-duplex mode | |
| of the 3c509B is enabled, its link partner will very likely need to be | |
| independently _forced_ into full-duplex mode as well; otherwise various nasty | |
| failures will occur - at the very least, you'll see massive numbers of packet | |
| collisions. This is one of very rare circumstances where disabling auto- | |
| negotiation and forcing the duplex mode of a network interface card or switch | |
| would ever be necessary or desirable. | |
| (3) Available Transceiver Types | |
| For versions of the driver v1.18c and above, the available transceiver types are: | |
| 0 transceiver type from EEPROM config (normally 10baseT); force half-duplex | |
| 1 AUI (thick-net / DB15 connector) | |
| 2 (undefined) | |
| 3 10base2 (thin-net == coax / BNC connector) | |
| 4 10baseT (RJ-45 connector); force half-duplex mode | |
| 8 transceiver type and duplex mode taken from card's EEPROM config settings | |
| 12 10baseT (RJ-45 connector); force full-duplex mode | |
| Prior to driver version 1.18c, only transceiver codes 0-4 were supported. Note | |
| that the new transceiver codes 8 and 12 are the *only* ones that will enable | |
| full-duplex mode, no matter what the card's detected EEPROM settings might be. | |
| This insured that merely upgrading the driver from an earlier version would | |
| never automatically enable full-duplex mode in an existing installation; | |
| it must always be explicitly enabled via one of these code in order to be | |
| activated. | |
| (4a) Interpretation of error messages and common problems | |
| Error Messages | |
| eth0: Infinite loop in interrupt, status 2011. | |
| These are "mostly harmless" message indicating that the driver had too much | |
| work during that interrupt cycle. With a status of 0x2011 you are receiving | |
| packets faster than they can be removed from the card. This should be rare | |
| or impossible in normal operation. Possible causes of this error report are: | |
| - a "green" mode enabled that slows the processor down when there is no | |
| keyboard activity. | |
| - some other device or device driver hogging the bus or disabling interrupts. | |
| Check /proc/interrupts for excessive interrupt counts. The timer tick | |
| interrupt should always be incrementing faster than the others. | |
| No received packets | |
| If a 3c509, 3c562 or 3c589 can successfully transmit packets, but never | |
| receives packets (as reported by /proc/net/dev or 'ifconfig') you likely | |
| have an interrupt line problem. Check /proc/interrupts to verify that the | |
| card is actually generating interrupts. If the interrupt count is not | |
| increasing you likely have a physical conflict with two devices trying to | |
| use the same ISA IRQ line. The common conflict is with a sound card on IRQ10 | |
| or IRQ5, and the easiest solution is to move the 3c509 to a different | |
| interrupt line. If the device is receiving packets but 'ping' doesn't work, | |
| you have a routing problem. | |
| Tx Carrier Errors Reported in /proc/net/dev | |
| If an EtherLink III appears to transmit packets, but the "Tx carrier errors" | |
| field in /proc/net/dev increments as quickly as the Tx packet count, you | |
| likely have an unterminated network or the incorrect media transceiver selected. | |
| 3c509B card is not detected on machines with an ISA PnP BIOS. | |
| While the updated driver works with most PnP BIOS programs, it does not work | |
| with all. This can be fixed by disabling PnP support using the 3Com-supplied | |
| setup program. | |
| 3c509 card is not detected on overclocked machines | |
| Increase the delay time in id_read_eeprom() from the current value, 500, | |
| to an absurdly high value, such as 5000. | |
| (4b) Decoding Status and Error Messages | |
| The bits in the main status register are: | |
| value description | |
| 0x01 Interrupt latch | |
| 0x02 Tx overrun, or Rx underrun | |
| 0x04 Tx complete | |
| 0x08 Tx FIFO room available | |
| 0x10 A complete Rx packet has arrived | |
| 0x20 A Rx packet has started to arrive | |
| 0x40 The driver has requested an interrupt | |
| 0x80 Statistics counter nearly full | |
| The bits in the transmit (Tx) status word are: | |
| value description | |
| 0x02 Out-of-window collision. | |
| 0x04 Status stack overflow (normally impossible). | |
| 0x08 16 collisions. | |
| 0x10 Tx underrun (not enough PCI bus bandwidth). | |
| 0x20 Tx jabber. | |
| 0x40 Tx interrupt requested. | |
| 0x80 Status is valid (this should always be set). | |
| When a transmit error occurs the driver produces a status message such as | |
| eth0: Transmit error, Tx status register 82 | |
| The two values typically seen here are: | |
| 0x82 | |
| Out of window collision. This typically occurs when some other Ethernet | |
| host is incorrectly set to full duplex on a half duplex network. | |
| 0x88 | |
| 16 collisions. This typically occurs when the network is exceptionally busy | |
| or when another host doesn't correctly back off after a collision. If this | |
| error is mixed with 0x82 errors it is the result of a host incorrectly set | |
| to full duplex (see above). | |
| Both of these errors are the result of network problems that should be | |
| corrected. They do not represent driver malfunction. | |
| (5) Revision history (this file) | |
| 28Feb02 v1.0 DR New; major portions based on Becker original 3c509 docs | |