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diff --git a/kernel/Documentation/networking/3c509.txt b/kernel/Documentation/networking/3c509.txt new file mode 100644 index 000000000..fbf722e15 --- /dev/null +++ b/kernel/Documentation/networking/3c509.txt @@ -0,0 +1,213 @@ +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) + 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 + |