e1000: update README for e1000

Linux* Base Driver for the Intel(R) PRO/1000 Family of Adapters

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

November 15, 2005

September 26, 2006

Contents

- In This Release

- Identifying Your Adapter

- Building and Installation

- Command Line Parameters

- Speed and Duplex Configuration

- Additional Configurations

Instructions on updating ethtool can be found in the section "Additional

Configurations" later in this document.

NOTE: The Intel(R) 82562v 10/100 Network Connection only provides 10/100

support.

Identifying Your Adapter

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

    http://downloadfinder.intel.com/scripts-df/support_intel.asp

Command Line Parameters =======================

Command Line Parameters

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

If the driver is built as a module, the  following optional parameters

are used by entering them on the command line with the modprobe or insmod

command using this syntax:

are used by entering them on the command line with the modprobe command

using this syntax:

     modprobe e1000 [<option>=<VAL1>,<VAL2>,...]

     insmod e1000 [<option>=<VAL1>,<VAL2>,...]

For example, with two PRO/1000 PCI adapters, entering:

     insmod e1000 TxDescriptors=80,128

     modprobe e1000 TxDescriptors=80,128

loads the e1000 driver with 80 TX descriptors for the first adapter and 128

TX descriptors for the second adapter.

loads the e1000 driver with 80 TX descriptors for the first adapter and

128 TX descriptors for the second adapter.

The default value for each parameter is generally the recommended setting,

unless otherwise noted.

Valid Range:   0x01-0x0F, 0x20-0x2F

Default Value: 0x2F

This parameter is a bit mask that specifies which speed and duplex

settings the board advertises. When this parameter is used, the Speed

and Duplex parameters must not be specified.

This parameter is a bit-mask that specifies the speed and duplex settings

advertised by the adapter.  When this parameter is used, the Speed and

Duplex parameters must not be specified.

NOTE:  Refer to the Speed and Duplex section of this readme for more

       information on the AutoNeg parameter.

Valid Range:   0-2 (0=auto-negotiate, 1=half, 2=full)

Default Value: 0

Defines the direction in which data is allowed to flow. Can be either

one or two-directional. If both Duplex and the link partner are set to

auto-negotiate, the board auto-detects the correct duplex. If the link

partner is forced (either full or half), Duplex defaults to half-duplex.

This defines the direction in which data is allowed to flow.  Can be

either one or two-directional.  If both Duplex and the link partner are

set to auto-negotiate, the board auto-detects the correct duplex.  If the

link partner is forced (either full or half), Duplex defaults to half-

duplex.

FlowControl

----------

-----------

Valid Range:   0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx)

Default Value: Reads flow control settings from the EEPROM

InterruptThrottleRate

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

(not supported on Intel 82542, 82543 or 82544-based adapters)

Valid Range:   100-100000 (0=off, 1=dynamic)

Default Value: 8000

This value represents the maximum number of interrupts per second the

controller generates. InterruptThrottleRate is another setting used in

interrupt moderation. Dynamic mode uses a heuristic algorithm to adjust

InterruptThrottleRate based on the current traffic load.

(not supported on Intel(R) 82542, 82543 or 82544-based adapters)

Valid Range:   0,1,3,100-100000 (0=off, 1=dynamic, 3=dynamic conservative)

Default Value: 3

The driver can limit the amount of interrupts per second that the adapter

will generate for incoming packets. It does this by writing a value to the 

adapter that is based on the maximum amount of interrupts that the adapter 

will generate per second.

Setting InterruptThrottleRate to a value greater or equal to 100

will program the adapter to send out a maximum of that many interrupts

per second, even if more packets have come in. This reduces interrupt

load on the system and can lower CPU utilization under heavy load,

but will increase latency as packets are not processed as quickly.

The default behaviour of the driver previously assumed a static 

InterruptThrottleRate value of 8000, providing a good fallback value for 

all traffic types,but lacking in small packet performance and latency. 

The hardware can handle many more small packets per second however, and 

for this reason an adaptive interrupt moderation algorithm was implemented.

Since 7.3.x, the driver has two adaptive modes (setting 1 or 3) in which

it dynamically adjusts the InterruptThrottleRate value based on the traffic 

that it receives. After determining the type of incoming traffic in the last

timeframe, it will adjust the InterruptThrottleRate to an appropriate value 

for that traffic.

The algorithm classifies the incoming traffic every interval into

classes.  Once the class is determined, the InterruptThrottleRate value is 

adjusted to suit that traffic type the best. There are three classes defined: 

"Bulk traffic", for large amounts of packets of normal size; "Low latency",

for small amounts of traffic and/or a significant percentage of small

packets; and "Lowest latency", for almost completely small packets or 

minimal traffic.

In dynamic conservative mode, the InterruptThrottleRate value is set to 4000 

for traffic that falls in class "Bulk traffic". If traffic falls in the "Low 

latency" or "Lowest latency" class, the InterruptThrottleRate is increased 

stepwise to 20000. This default mode is suitable for most applications.

For situations where low latency is vital such as cluster or

grid computing, the algorithm can reduce latency even more when

InterruptThrottleRate is set to mode 1. In this mode, which operates

the same as mode 3, the InterruptThrottleRate will be increased stepwise to 

70000 for traffic in class "Lowest latency".

Setting InterruptThrottleRate to 0 turns off any interrupt moderation

and may improve small packet latency, but is generally not suitable

for bulk throughput traffic.

NOTE:  InterruptThrottleRate takes precedence over the TxAbsIntDelay and

       RxAbsIntDelay parameters.  In other words, minimizing the receive

       generate more interrupts than what the Interrupt Throttle Rate

       allows.

CAUTION:  If you are using the Intel PRO/1000 CT Network Connection

CAUTION:  If you are using the Intel(R) PRO/1000 CT Network Connection

          (controller 82547), setting InterruptThrottleRate to a value

          greater than 75,000, may hang (stop transmitting) adapters

          under certain network conditions.  If this occurs a NETDEV

       the overall throughput, we recommend that you load the driver as

       follows:

           insmod e1000.o InterruptThrottleRate=3000,3000,3000

           modprobe e1000 InterruptThrottleRate=3000,3000,3000

       This sets the InterruptThrottleRate to 3000 interrupts/sec for

       the first, second, and third instances of the driver.  The range

       RX_POLLING (NAPI) and default driver settings.

RxDescriptors

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

Valid Range:   80-256 for 82542 and 82543-based adapters

               80-4096 for all other supported adapters

Default Value: 256

This value specifies the number of receive descriptors allocated by the

driver. Increasing this value allows the driver to buffer more incoming

packets.  Each descriptor is 16 bytes.  A receive buffer is also

allocated for each descriptor and is 2048.

This value specifies the number of receive buffer descriptors allocated

by the driver.  Increasing this value allows the driver to buffer more

incoming packets, at the expense of increased system memory utilization.

Each descriptor is 16 bytes.  A receive buffer is also allocated for each

descriptor and can be either 2048, 4096, 8192, or 16384 bytes, depending 

on the MTU setting. The maximum MTU size is 16110.

NOTE:  MTU designates the frame size.  It only needs to be set for Jumbo 

       Frames.  Depending on the available system resources, the request 

       for a higher number of receive descriptors may be denied.  In this 

       case, use a lower number.

RxIntDelay

speed and duplex combinations are advertised during the auto-negotiation

process.

The parameter may be specified as either a decimal or hexidecimal value as

The parameter may be specified as either a decimal or hexadecimal value as

determined by the bitmap below.

Bit position   7      6      5       4       3      2      1       0

  Configuring the Driver on Different Distributions

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

  Configuring a network driver to load properly when the system is started

  is distribution dependent.  Typically, the configuration process involves

  adding an alias line to /etc/modules.conf or /etc/modprobe.conf as well

  To learn the proper way to configure a network device for your system,

  refer to your distribution documentation.  If during this process you are

  asked for the driver or module name, the name for the Linux Base Driver

  for the Intel PRO/1000 Family of Adapters is e1000.

  for the Intel(R) PRO/1000 Family of Adapters is e1000.

  As an example, if you install the e1000 driver for two PRO/1000 adapters

  (eth0 and eth1) and set the speed and duplex to 10full and 100half, add

  the following to modules.conf or modprobe.conf:

  the following to modules.conf or or modprobe.conf:

       alias eth0 e1000

       alias eth1 e1000

  Viewing Link Messages

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

  Link messages will not be displayed to the console if the distribution is

  restricting system messages.  In order to see network driver link messages

  on your console, set dmesg to eight by entering the following:

  Jumbo Frames

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

  The driver supports Jumbo Frames for all adapters except 82542 and

  82573-based adapters. Jumbo Frames support is enabled by changing the

  MTU to a value larger than the default of 1500. Use the ifconfig command

  to increase the MTU size. For example:

  Jumbo Frames support is enabled by changing the MTU to a value larger than

  the default of 1500.  Use the ifconfig command to increase the MTU size.

  For example:

       ifconfig eth<x> mtu 9000 up

  - To enable Jumbo Frames, increase the MTU size on the interface beyond

    1500.

  - The maximum MTU setting for Jumbo Frames is 16110.  This value coincides

    with the maximum Jumbo Frames size of 16128.

  - Using Jumbo Frames at 10 or 100 Mbps may result in poor performance or

    loss of link.

  - Some Intel gigabit adapters that support Jumbo Frames have a frame size

    limit of 9238 bytes, with a corresponding MTU size limit of 9216 bytes.

    The adapters with this limitation are based on the Intel 82571EB and

    82572EI controllers, which correspond to these product names:

     Intel® PRO/1000 PT Dual Port Server Adapter

     Intel® PRO/1000 PF Dual Port Server Adapter

     Intel® PRO/1000 PT Server Adapter

     Intel® PRO/1000 PT Desktop Adapter

     Intel® PRO/1000 PF Server Adapter

  - The Intel PRO/1000 PM Network Connection does not support jumbo frames.

    The adapters with this limitation are based on the Intel(R) 82571EB,

    82572EI, 82573L and 80003ES2LAN controller.  These correspond to the

    following product names:

     Intel(R) PRO/1000 PT Server Adapter

     Intel(R) PRO/1000 PT Desktop Adapter

     Intel(R) PRO/1000 PT Network Connection

     Intel(R) PRO/1000 PT Dual Port Server Adapter

     Intel(R) PRO/1000 PT Dual Port Network Connection

     Intel(R) PRO/1000 PF Server Adapter

     Intel(R) PRO/1000 PF Network Connection

     Intel(R) PRO/1000 PF Dual Port Server Adapter

     Intel(R) PRO/1000 PB Server Connection

     Intel(R) PRO/1000 PL Network Connection

     Intel(R) PRO/1000 EB Network Connection with I/O Acceleration

     Intel(R) PRO/1000 EB Backplane Connection with I/O Acceleration

     Intel(R) PRO/1000 PT Quad Port Server Adapter

  - Adapters based on the Intel(R) 82542 and 82573V/E controller do not

    support Jumbo Frames. These correspond to the following product names:

     Intel(R) PRO/1000 Gigabit Server Adapter

     Intel(R) PRO/1000 PM Network Connection

  - The following adapters do not support Jumbo Frames:

     Intel(R) 82562V 10/100 Network Connection

     Intel(R) 82566DM Gigabit Network Connection

     Intel(R) 82566DC Gigabit Network Connection

     Intel(R) 82566MM Gigabit Network Connection

     Intel(R) 82566MC Gigabit Network Connection

     Intel(R) 82562GT 10/100 Network Connection

     Intel(R) 82562G 10/100 Network Connection

  Ethtool

  -------

  The driver utilizes the ethtool interface for driver configuration and

  diagnostics, as well as displaying statistical information.  Ethtool

  version 1.6 or later is required for this functionality.

  Enabling Wake on LAN* (WoL)

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

  WoL is configured through the Ethtool* utility.  Ethtool is included with

  all versions of Red Hat after Red Hat 7.2.  For other Linux distributions,

  download and install Ethtool from the following website:

  For this driver version, in order to enable WoL, the e1000 driver must be

  loaded when shutting down or rebooting the system.

  Wake On LAN is only supported on port A for the following devices:

  Intel(R) PRO/1000 PT Dual Port Network Connection

  Intel(R) PRO/1000 PT Dual Port Server Connection

  Intel(R) PRO/1000 PT Dual Port Server Adapter

  Intel(R) PRO/1000 PF Dual Port Server Adapter

  Intel(R) PRO/1000 PT Quad Port Server Adapter 

  NAPI

  ----

  NAPI (Rx polling mode) is supported in the e1000 driver.  NAPI is enabled

  or disabled based on the configuration of the kernel.  To override

  the default, use the following compile-time flags.

Known Issues

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

Dropped Receive Packets on Half-duplex 10/100 Networks

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

If you have an Intel PCI Express adapter running at 10mbps or 100mbps, half-

duplex, you may observe occasional dropped receive packets.  There are no

workarounds for this problem in this network configuration.  The network must

be updated to operate in full-duplex, and/or 1000mbps only.

Jumbo Frames System Requirement

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

Memory allocation failures have been observed on Linux systems with 64 MB

of RAM or less that are running Jumbo Frames.  If you are using Jumbo

Frames, your system may require more than the advertised minimum

Performance Degradation with Jumbo Frames

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

Degradation in throughput performance may be observed in some Jumbo frames

environments.  If this is observed, increasing the application's socket

buffer size and/or increasing the /proc/sys/net/ipv4/tcp_*mem entry values

/usr/src/linux*/Documentation/

networking/ip-sysctl.txt for more details.

  Jumbo frames on Foundry BigIron 8000 switch

Jumbo Frames on Foundry BigIron 8000 switch

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

There is a known issue using Jumbo frames when connected to a Foundry

BigIron 8000 switch.  This is a 3rd party limitation.  If you experience

loss of packets, lower the MTU size.

Allocating Rx Buffers when Using Jumbo Frames 

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

Allocating Rx buffers when using Jumbo Frames on 2.6.x kernels may fail if 

the available memory is heavily fragmented. This issue may be seen with PCI-X 

adapters or with packet split disabled. This can be reduced or eliminated 

by changing the amount of available memory for receive buffer allocation, by

increasing /proc/sys/vm/min_free_kbytes. 

Multiple Interfaces on Same Ethernet Broadcast Network

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

Due to the default ARP behavior on Linux, it is not possible to have

one system on two IP networks in the same Ethernet broadcast domain

(non-partitioned switch) behave as expected.  All Ethernet interfaces

82541/82547 can't link or are slow to link with some link partners

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

There is a known compatibility issue with 82541/82547 and some

low-end switches where the link will not be established, or will

be slow to establish.  In particular, these switches are known to

of the PHY's master/slave setting.  Forcing master or forcing slave

mode will improve time-to-link.

      # make EXTRA_CFLAGS=-DE1000_MASTER_SLAVE=<n>

    # make CFLAGS_EXTRA=-DE1000_MASTER_SLAVE=<n>

Where <n> is:

Disable rx flow control with ethtool

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

In order to disable receive flow control using ethtool, you must turn

off auto-negotiation on the same command line.

   ethtool -A eth? autoneg off rx off

Unplugging network cable while ethtool -p is running

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

In kernel versions 2.5.50 and later (including 2.6 kernel), unplugging

the network cable while ethtool -p is running will cause the system to

become unresponsive to keyboard commands, except for control-alt-delete.

Restarting the system appears to be the only remedy.

Support

=======

If an issue is identified with the released source code on the supported

kernel with a supported adapter, email the specific information related

to the issue to e1000-devel@lists.sourceforge.net

License

=======

This software program is released under the terms of a license agreement

between you ('Licensee') and Intel. Do not use or load this software or any

associated materials (collectively, the 'Software') until you have carefully

read the full terms and conditions of the file COPYING located in this software

package. By loading or using the Software, you agree to the terms of this

Agreement. If you do not agree with the terms of this Agreement, do not

install or use the Software.

* Other names and brands may be claimed as the property of others.

to the issue to e1000-devel@lists.sf.net