| 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 <[email protected]> | 
 |  | 
 | ---------------------------------------------------------------------------- | 
 |  | 
 | (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/. | 
 |  | 
 |  | 
 | (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 may be overridden. For example, | 
 | setting two cards to IRQ10 and IRQ11 is done by using the irq module | 
 | option: | 
 |  | 
 |    options 3c509 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. | 
 |  | 
 | Full-duplex mode can be enabled using 'ethtool'. | 
 |   | 
 | /////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. | 
 |  | 
 | The transceiver type can be changed using 'ethtool'. | 
 |    | 
 |  | 
 | (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 | 
 |  |