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Documentation/networking/vortex.txt

Andrew Morton 

30 April 2000

This document describes the usage and errata of the 3Com "Vortex" device

driver for Linux, 3c59x.c.

The driver was written by Donald Becker 

Don is no longer the prime maintainer of this version of the driver.

Please report problems to one or more of:

  Andrew Morton 

  Netdev mailing list 

  Linux kernel mailing list 

Please note the 'Reporting and Diagnosing Problems' section at the end

of this file.

Since kernel 2.3.99-pre6, this driver incorporates the support for the

3c575-series Cardbus cards which used to be handled by 3c575_cb.c.

This driver supports the following hardware:

   3c590 Vortex 10Mbps

   3c592 EISA 10mbps Demon/Vortex

   3c597 EISA Fast Demon/Vortex

   3c595 Vortex 100baseTx

   3c595 Vortex 100baseT4

   3c595 Vortex 100base-MII

   3Com Vortex

   3c900 Boomerang 10baseT

   3c900 Boomerang 10Mbps Combo

   3c900 Cyclone 10Mbps TPO

   3c900B Cyclone 10Mbps T

   3c900 Cyclone 10Mbps Combo

   3c900 Cyclone 10Mbps TPC

   3c900B-FL Cyclone 10base-FL

   3c905 Boomerang 100baseTx

   3c905 Boomerang 100baseT4

   3c905B Cyclone 100baseTx

   3c905B Cyclone 10/100/BNC

   3c905B-FX Cyclone 100baseFx

   3c905C Tornado

   3c980 Cyclone

   3cSOHO100-TX Hurricane

   3c555 Laptop Hurricane

   3c575 Boomerang CardBus

   3CCFE575 Cyclone CardBus

   3CCFE575CT Cyclone CardBus

   3CCFE656 Cyclone CardBus

   3CCFEM656 Cyclone CardBus

   3c450 Cyclone/unknown

Module parameters

=================

There are several parameters which may be provided to the driver when

its module is loaded.  These are usually placed in /etc/modules.conf

(used to be conf.modules).  Example:

options 3c59x debug=3 rx_copybreak=300

If you are using the PCMCIA tools (cardmgr) then the options may be

placed in /etc/pcmcia/config.opts:

module "3c59x" opts "debug=3 rx_copybreak=300"

The supported parameters are:

debug=N

  Where N is a number from 0 to 7.  Anything above 3 produces a lot

  of output in your system logs.  debug=1 is default.

options=N1,N2,N3,...

  Each number in the list provides an option to the corresponding

  network card.  So if you have two 3c905's and you wish to provide

  them with option 0x204 you would use:

    options=0x204,0x204

  The individual options are composed of a number of bitfields which

  have the following meanings:

  Possible media type settings

        1       10Mbs AUI

        2       undefined

        3       10base2 (BNC)

        4       100base-TX

        5       100base-FX

        6       MII (Media Independent Interface)

        7       Use default setting from EEPROM

        8       Autonegotiate

        9       External MII

        10      Use default setting from EEPROM

  When generating a value for the 'options' setting, the above media

  selection values may be OR'ed (or added to) the following:

  0x8000  Set driver debugging level to 7

  0x4000  Set driver debugging level to 2

  0x0400  Enable Wake-on-LAN

  0x0200  Force full duplex mode.

  0x0010  Bus-master enable bit (Old Vortex cards only)

  For example:

    insmod 3c59x options=0x204

  will force full-duplex 100base-TX, rather than allowing the usual

  autonegotiation.

global_options=N

  Sets the `options' parameter for all 3c59x NICs in the machine.

  Entries in the `options' array above will override any setting of

  this.

full_duplex=N1,N2,N3...

  Similar to bit 9 of 'options'.  Forces the corresponding card into

  full-duplex mode.  Please use this in preference to the `options'

  parameter.

  In fact, please don't use this at all! You're better off getting

  autonegotiation working properly.

global_full_duplex=N1

  Sets full duplex mode for all 3c59x NICs in the machine.  Entries

  in the `full_duplex' array above will override any setting of this.

flow_ctrl=N1,N2,N3...

  Use 802.3x MAC-layer flow control.  The 3com cards only support the

  PAUSE command, which means that they will stop sending packets for a

  short period if they receive a PAUSE frame from the link partner.

  The driver only allows flow control on a link which is operating in

  full duplex mode.

  This feature does not appear to work on the 3c905 - only 3c905B and

  3c905C have been tested.

  The 3com cards appear to only respond to PAUSE frames which are

  sent to the reserved destination address of 01:80:c2:00:00:01.  They

  do not honour PAUSE frames which are sent to the station MAC address.

rx_copybreak=M

  The driver preallocates 32 full-sized (1536 byte) network buffers

  for receiving.  When a packet arrives, the driver has to decide

  whether to leave the packet in its full-sized buffer, or to allocate

  a smaller buffer and copy the packet across into it.

  This is a speed/space tradeoff.

  The value of rx_copybreak is used to decide when to make the copy.

  If the packet size is less than rx_copybreak, the packet is copied.

  The default value for rx_copybreak is 200 bytes.

max_interrupt_work=N

  The driver's interrupt service routine can handle many receive and

  transmit packets in a single invocation.  It does this in a loop.

  The value of max_interrupt_work governs how mnay times the interrupt

  service routine will loop.  The default value is 32 loops.  If this

  is exceeded the interrupt service routine gives up and generates a

  warning message "eth0: Too much work in interrupt".

hw_checksums=N1,N2,N3,...

  Recent 3com NICs are able to generate IPv4, TCP and UDP checksums

  in hardware.  Linux has used the Rx checksumming for a long time.

  The "zero copy" patch which is planned for the 2.4 kernel series

  allows you to make use of the NIC's DMA scatter/gather and transmit

  checksumming as well.

  The driver is set up so that, when the zerocopy patch is applied,

  all Tornado and Cyclone devices will use S/G and Tx checksums.

  This module parameter has been provided so you can override this

  decision.  If you think that Tx checksums are causing a problem, you

  may disable the feature with `hw_checksums=0'.

  If you think your NIC should be performing Tx checksumming and the

  driver isn't enabling it, you can force the use of hardware Tx

  checksumming with `hw_checksums=1'.

  The driver drops a message in the logfiles to indicate whether or

  not it is using hardware scatter/gather and hardware Tx checksums.

  Scatter/gather and hardware checksums provide considerable

  performance improvement for the sendfile() system call, but a small

  decrease in throughput for send().  There is no effect upon receive

  efficiency.

compaq_ioaddr=N

compaq_irq=N

compaq_device_id=N

  "Variables to work-around the Compaq PCI BIOS32 problem"....

watchdog=N

  Sets the time duration (in milliseconds) after which the kernel

  decides that the transmitter has become stuck and needs to be reset.

  This is mainly for debugging purposes, although it may be advantageous

  to increase this value on LANs which have very high collision rates.

  The default value is 5000 (5.0 seconds).

enable_wol=N1,N2,N3,...

  Enable Wake-on-LAN support for the relevant interface.  Donald

  Becker's `ether-wake' application may be used to wake suspended

  machines.

  Also enables the NIC's power management support.

global_enable_wol=N

  Sets enable_wol mode for all 3c59x NICs in the machine.  Entries in

  the `enable_wol' array above will override any setting of this.

Media selection

---------------

A number of the older NICs such as the 3c590 and 3c900 series have

10base2 and AUI interfaces.

Prior to January, 2001 this driver would autoeselect the 10base2 or AUI

port if it didn't detect activity on the 10baseT port.  It would then

get stuck on the 10base2 port and a driver reload was necessary to

switch back to 10baseT.  This behaviour could not be prevented with a

module option override.

Later (current) versions of the driver _do_ support locking of the

media type.  So if you load the driver module with

        modprobe 3c59x options=0

it will permanently select the 10baseT port.  Automatic selection of

other media types does not occur.

Transmit error, Tx status register 82

-------------------------------------

This is a common error which is almost always caused by another host on

the same network being in full-duplex mode, while this host is in

half-duplex mode.  You need to find that other host and make it run in

half-duplex mode or fix this host to run in full-duplex mode.

As a last resort, you can force the 3c59x driver into full-duplex mode

with

        options 3c59x full_duplex=1

but this has to be viewed as a workaround for broken network gear and

should only really be used for equipment which cannot autonegotiate.

Additional resources

--------------------

Details of the device driver implementation are at the top of the source file.

Additional documentation is available at Don Becker's Linux Drivers site:

  http://www.scyld.com/network/vortex.html

Donald Becker's driver development site:

     http://www.scyld.com/network

Donald's vortex-diag program is useful for inspecting the NIC's state:

     http://www.scyld.com/diag/#pci-diags

Donald's mii-diag program may be used for inspecting and manipulating

the NIC's Media Independent Interface subsystem:

     http://www.scyld.com/diag/#mii-diag

Donald's wake-on-LAN page:

     http://www.scyld.com/expert/wake-on-lan.html

3Com's documentation for many NICs, including the ones supported by

this driver is available at

     http://support.3com.com/partners/developer/developer_form.html

3Com's DOS-based application for setting up the NICs EEPROMs:

        ftp://ftp.3com.com/pub/nic/3c90x/3c90xx2.exe

Driver updates and a detailed changelog for the modifications which

were made for the 2.3/2,4 series kernel is available at

     http://www.uow.edu.au/~andrewm/linux/#3c59x-2.3

Autonegotiation notes

---------------------

  The driver uses a one-minute heartbeat for adapting to changes in

  the external LAN environment.  This means that when, for example, a

  machine is unplugged from a hubbed 10baseT LAN plugged into a

  switched 100baseT LAN, the throughput will be quite dreadful for up

  to sixty seconds.  Be patient.

  Cisco interoperability note from Walter Wong :

  On a side note, adding HAS_NWAY seems to share a problem with the

  Cisco 6509 switch.  Specifically, you need to change the spanning

  tree parameter for the port the machine is plugged into to 'portfast'

  mode.  Otherwise, the negotiation fails.  This has been an issue

  we've noticed for a while but haven't had the time to track down.

  Cisco switches    (Jeff Busch )

    My "standard config" for ports to which PC's/servers connect directly:

        interface FastEthernet0/N

        description machinename

        load-interval 30

        spanning-tree portfast

    If autonegotiation is a problem, you may need to specify "speed

    100" and "duplex full" as well (or "speed 10" and "duplex half").

    WARNING: DO NOT hook up hubs/switches/bridges to these

    specially-configured ports! The switch will become very confused.

Reporting and diagnosing problems

---------------------------------

Maintainers find that accurate and complete problem reports are

invaluable in resolving driver problems.  We are frequently not able to

reproduce problems and must rely on your patience and efforts to get to

the bottom of the problem.

If you believe you have a driver problem here are some of the

steps you should take:

- Is it really a driver problem?

   Eliminate some variables: try different cards, different

   computers, different cables, different ports on the switch/hub,

   different versions of the kernel or ofthe driver, etc.

- OK, it's a driver problem.

   You need to generate a report.  Typically this is an email to the

   maintainer and/or linux-net@vger.kernel.org.  The maintainer's

   email address will be inthe driver source or in the MAINTAINERS file.

- The contents of your report will vary a lot depending upon the

  problem.  If it's a kernel crash then you should refer to the

  REPORTING-BUGS file.

  But for most problems it is useful to provide the following:

   o Kernel version, driver version

   o A copy of the banner message which the driver generates when

     it is initialised.  For example:

     eth0: 3Com PCI 3c905C Tornado at 0xa400,  00:50:da:6a:88:f0, IRQ 19

     8K byte-wide RAM 5:3 Rx:Tx split, autoselect/Autonegotiate interface.

     MII transceiver found at address 24, status 782d.

     Enabling bus-master transmits and whole-frame receives.

     NOTE: You must provide the `debug=2' modprobe option to generate

     a full detection message.  Please do this:

        modprobe 3c59x debug=2

   o If it is a PCI device, the relevant output from 'lspci -vx', eg:

     00:09.0 Ethernet controller: 3Com Corporation 3c905C-TX [Fast Etherlink] (rev 74)

             Subsystem: 3Com Corporation: Unknown device 9200

             Flags: bus master, medium devsel, latency 32, IRQ 19

             I/O ports at a400 [size=128]

             Memory at db000000 (32-bit, non-prefetchable) [size=128]

             Expansion ROM at  [disabled] [size=128K]

             Capabilities: [dc] Power Management version 2

     00: b7 10 00 92 07 00 10 02 74 00 00 02 08 20 00 00

     10: 01 a4 00 00 00 00 00 db 00 00 00 00 00 00 00 00

     20: 00 00 00 00 00 00 00 00 00 00 00 00 b7 10 00 10

     30: 00 00 00 00 dc 00 00 00 00 00 00 00 05 01 0a 0a

   o A description of the environment: 10baseT? 100baseT?

     full/half duplex? switched or hubbed?

   o Any additional module parameters which you may be providing to the driver.

   o Any kernel logs which are produced.  The more the merrier.

     If this is a large file and you are sending your report to a

     mailing list, mention that you have the logfile, but don't send

     it.  If you're reporting direct to the maintainer then just send

     it.

     To ensure that all kernel logs are available, add the

     following line to /etc/syslog.conf:

         kern.* /var/log/messages

     Then restart syslogd with:

         /etc/rc.d/init.d/syslog restart

     (The above may vary, depending upon which Linux distribution you use).

    o If your problem is reproducible then that's great.  Try the

      following:

      1) Increase the debug level.  Usually this is done via:

         a) modprobe driver.o debug=7

         b) In /etc/conf.modules (or modules.conf):

            options driver_name debug=7

      2) Recreate the problem with the higher debug level,

         send all logs to the maintainer.

      3) Download you card's diagnostic tool from Donald

         Backer's website http://www.scyld.com/diag.  Download

         mii-diag.c as well.  Build these.

         a) Run 'vortex-diag -aaee' and 'mii-diag -v' when the card is

            working correctly.  Save the output.

         b) Run the above commands when the card is malfunctioning.  Send

            both sets of output.

Finally, please be patient and be prepared to do some work.  You may end up working on

this problem for a week or more as the maintainer asks more questions, asks for more

tests, asks for patches to be applied, etc.  At the end of it all, the problem may even

remain unresolved.