Documentation/networking/e1000.txt - kernel/msm-5.4 - Gitiles

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

 November 15, 2005


 Contents
 ========

 - In This Release
 - Identifying Your Adapter
 - Command Line Parameters
 - Speed and Duplex Configuration
 - Additional Configurations
 - Known Issues
 - Support


 In This Release
 ===============

 This file describes the Linux* Base Driver for the Intel(R) PRO/1000 Family
 of Adapters.  This driver includes support for Itanium(R)2-based systems.

 For questions related to hardware requirements, refer to the documentation
 supplied with your Intel PRO/1000 adapter. All hardware requirements listed
 apply to use with Linux.

 The following features are now available in supported kernels:
  - Native VLANs
  - Channel Bonding (teaming)
  - SNMP

 Channel Bonding documentation can be found in the Linux kernel source:
 /Documentation/networking/bonding.txt

 The driver information previously displayed in the /proc filesystem is not
 supported in this release.  Alternatively, you can use ethtool (version 1.6
 or later), lspci, and ifconfig to obtain the same information.

 Instructions on updating ethtool can be found in the section "Additional
 Configurations" later in this document.


 Identifying Your Adapter
 ========================

 For more information on how to identify your adapter, go to the Adapter &
 Driver ID Guide at:

     http://support.intel.com/support/network/adapter/pro100/21397.htm

 For the latest Intel network drivers for Linux, refer to the following
 website. In the search field, enter your adapter name or type, or use the
 networking link on the left to search for your adapter:

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


 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:

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

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

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

      insmod e1000 TxDescriptors=80,128

 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.

 NOTES:  For more information about the AutoNeg, Duplex, and Speed
         parameters, see the "Speed and Duplex Configuration" section in
         this document.

         For more information about the InterruptThrottleRate,
         RxIntDelay, TxIntDelay, RxAbsIntDelay, and TxAbsIntDelay
         parameters, see the application note at:
         http://www.intel.com/design/network/applnots/ap450.htm

         A descriptor describes a data buffer and attributes related to
         the data buffer. This information is accessed by the hardware.


 AutoNeg
 -------
 (Supported only on adapters with copper connections)
 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.

 NOTE:  Refer to the Speed and Duplex section of this readme for more
        information on the AutoNeg parameter.


 Duplex
 ------
 (Supported only on adapters with copper connections)
 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.


 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

 This parameter controls the automatic generation(Tx) and response(Rx)
 to Ethernet PAUSE frames.


 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.

 NOTE:  InterruptThrottleRate takes precedence over the TxAbsIntDelay and
        RxAbsIntDelay parameters. In other words, minimizing the receive
        and/or transmit absolute delays does not force the controller to
        generate more interrupts than what the Interrupt Throttle Rate
        allows.

 CAUTION:  If you are using the Intel 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
           WATCHDOG message is logged in the system event log. In
           addition, the controller is automatically reset, restoring
           the network connection. To eliminate the potential for the
           hang, ensure that InterruptThrottleRate is set no greater
           than 75,000 and is not set to 0.

 NOTE:  When e1000 is loaded with default settings and multiple adapters
        are in use simultaneously, the CPU utilization may increase non-
        linearly. In order to limit the CPU utilization without impacting
        the overall throughput, we recommend that you load the driver as
        follows:

            insmod e1000.o InterruptThrottleRate=3000,3000,3000

        This sets the InterruptThrottleRate to 3000 interrupts/sec for
        the first, second, and third instances of the driver. The range
        of 2000 to 3000 interrupts per second works on a majority of
        systems and is a good starting point, but the optimal value will
        be platform-specific. If CPU utilization is not a concern, use
        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.


 RxIntDelay
 ----------
 Valid Range:   0-65535 (0=off)
 Default Value: 0

 This value delays the generation of receive interrupts in units of 1.024
 microseconds.  Receive interrupt reduction can improve CPU efficiency if
 properly tuned for specific network traffic. Increasing this value adds
 extra latency to frame reception and can end up decreasing the throughput
 of TCP traffic. If the system is reporting dropped receives, this value
 may be set too high, causing the driver to run out of available receive
 descriptors.

 CAUTION:  When setting RxIntDelay to a value other than 0, adapters may
           hang (stop transmitting) under certain network conditions. If
           this occurs a NETDEV WATCHDOG message is logged in the system
           event log. In addition, the controller is automatically reset,
           restoring the network connection. To eliminate the potential
           for the hang ensure that RxIntDelay is set to 0.


 RxAbsIntDelay
 -------------
 (This parameter is supported only on 82540, 82545 and later adapters.)
 Valid Range:   0-65535 (0=off)
 Default Value: 128

 This value, in units of 1.024 microseconds, limits the delay in which a
 receive interrupt is generated. Useful only if RxIntDelay is non-zero,
 this value ensures that an interrupt is generated after the initial
 packet is received within the set amount of time.  Proper tuning,
 along with RxIntDelay, may improve traffic throughput in specific network
 conditions.


 Speed
 -----
 (This parameter is supported only on adapters with copper connections.)
 Valid Settings: 0, 10, 100, 1000
 Default Value:  0 (auto-negotiate at all supported speeds)

 Speed forces the line speed to the specified value in megabits per second
 (Mbps). If this parameter is not specified or is set to 0 and the link
 partner is set to auto-negotiate, the board will auto-detect the correct
 speed. Duplex should also be set when Speed is set to either 10 or 100.


 TxDescriptors
 -------------
 Valid Range:   80-256 for 82542 and 82543-based adapters
                80-4096 for all other supported adapters
 Default Value: 256

 This value is the number of transmit descriptors allocated by the driver.
 Increasing this value allows the driver to queue more transmits. Each
 descriptor is 16 bytes.

 NOTE:  Depending on the available system resources, the request for a
        higher number of transmit descriptors may be denied.  In this case,
        use a lower number.


 TxIntDelay
 ----------
 Valid Range:   0-65535 (0=off)
 Default Value: 64

 This value delays the generation of transmit interrupts in units of
 1.024 microseconds. Transmit interrupt reduction can improve CPU
 efficiency if properly tuned for specific network traffic. If the
 system is reporting dropped transmits, this value may be set too high
 causing the driver to run out of available transmit descriptors.


 TxAbsIntDelay
 -------------
 (This parameter is supported only on 82540, 82545 and later adapters.)
 Valid Range:   0-65535 (0=off)
 Default Value: 64

 This value, in units of 1.024 microseconds, limits the delay in which a
 transmit interrupt is generated. Useful only if TxIntDelay is non-zero,
 this value ensures that an interrupt is generated after the initial
 packet is sent on the wire within the set amount of time.  Proper tuning,
 along with TxIntDelay, may improve traffic throughput in specific
 network conditions.

 XsumRX
 ------
 (This parameter is NOT supported on the 82542-based adapter.)
 Valid Range:   0-1
 Default Value: 1

 A value of '1' indicates that the driver should enable IP checksum
 offload for received packets (both UDP and TCP) to the adapter hardware.


 Speed and Duplex Configuration
 ==============================

 Three keywords are used to control the speed and duplex configuration.
 These keywords are Speed, Duplex, and AutoNeg.

 If the board uses a fiber interface, these keywords are ignored, and the
 fiber interface board only links at 1000 Mbps full-duplex.

 For copper-based boards, the keywords interact as follows:

   The default operation is auto-negotiate. The board advertises all
   supported speed and duplex combinations, and it links at the highest
   common speed and duplex mode IF the link partner is set to auto-negotiate.

   If Speed = 1000, limited auto-negotiation is enabled and only 1000 Mbps
   is advertised (The 1000BaseT spec requires auto-negotiation.)

   If Speed = 10 or 100, then both Speed and Duplex should be set. Auto-
   negotiation is disabled, and the AutoNeg parameter is ignored. Partner
   SHOULD also be forced.

 The AutoNeg parameter is used when more control is required over the
 auto-negotiation process.  It should be used when you wish to control which
 speed and duplex combinations are advertised during the auto-negotiation
 process.

 The parameter may be specified as either a decimal or hexidecimal value as
 determined by the bitmap below.

 Bit position   7      6      5       4       3      2      1       0
 Decimal Value  128    64     32      16      8      4      2       1
 Hex value      80     40     20      10      8      4      2       1
 Speed (Mbps)   N/A    N/A    1000    N/A     100    100    10      10
 Duplex                       Full            Full   Half   Full    Half

 Some examples of using AutoNeg:

   modprobe e1000 AutoNeg=0x01 (Restricts autonegotiation to 10 Half)
   modprobe e1000 AutoNeg=1 (Same as above)
   modprobe e1000 AutoNeg=0x02 (Restricts autonegotiation to 10 Full)
   modprobe e1000 AutoNeg=0x03 (Restricts autonegotiation to 10 Half or 10 Full)
   modprobe e1000 AutoNeg=0x04 (Restricts autonegotiation to 100 Half)
   modprobe e1000 AutoNeg=0x05 (Restricts autonegotiation to 10 Half or 100
   Half)
   modprobe e1000 AutoNeg=0x020 (Restricts autonegotiation to 1000 Full)
   modprobe e1000 AutoNeg=32 (Same as above)

 Note that when this parameter is used, Speed and Duplex must not be specified.

 If the link partner is forced to a specific speed and duplex, then this
 parameter should not be used.  Instead, use the Speed and Duplex parameters
 previously mentioned to force the adapter to the same speed and duplex.


 Additional Configurations
 =========================

   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
   as editing other system startup scripts and/or configuration files. Many
   popular Linux distributions ship with tools to make these changes for you.
   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.

   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 or modprobe.conf:

        alias eth0 e1000
        alias eth1 e1000
        options e1000 Speed=10,100 Duplex=2,1

   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:

        dmesg -n 8

   NOTE: This setting is not saved across reboots.

   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:

        ifconfig eth<x> mtu 9000 up

   This setting is not saved across reboots.  It can be made permanent if
   you add:

        MTU=9000

    to the file /etc/sysconfig/network-scripts/ifcfg-eth<x>.  This example
    applies to the Red Hat distributions; other distributions may store this
    setting in a different location.

   Notes:

   - 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.


   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.

   The latest release of ethtool can be found from
   http://sourceforge.net/projects/gkernel.

   NOTE: Ethtool 1.6 only supports a limited set of ethtool options. Support
   for a more complete ethtool feature set can be enabled by upgrading
   ethtool to ethtool-1.8.1.

   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:
   http://sourceforge.net/projects/gkernel.

   For instructions on enabling WoL with Ethtool, refer to the website listed
   above.

   WoL will be enabled on the system during the next shut down or reboot.
   For this driver version, in order to enable WoL, the e1000 driver must be
   loaded when shutting down or rebooting the system.

   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.

   To enable NAPI, compile the driver module, passing in a configuration option:

        make CFLAGS_EXTRA=-DE1000_NAPI install

   To disable NAPI, compile the driver module, passing in a configuration option:

        make CFLAGS_EXTRA=-DE1000_NO_NAPI install

   See www.cyberus.ca/~hadi/usenix-paper.tgz for more information on NAPI.


 Known Issues
 ============

   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
   requirement of 64 MB of system memory.

   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
   may help. See the specific application manual and
   /usr/src/linux*/Documentation/
   networking/ip-sysctl.txt for more details.

   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.

   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
   will respond to IP traffic for any IP address assigned to the system.
   This results in unbalanced receive traffic.

   If you have multiple interfaces in a server, either turn on ARP
   filtering by entering:

       echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter
   (this only works if your kernel's version is higher than 2.4.5),

   NOTE: This setting is not saved across reboots. The configuration
   change can be made permanent by adding the line:
       net.ipv4.conf.all.arp_filter = 1
   to the file /etc/sysctl.conf

         or,

   install the interfaces in separate broadcast domains (either in
   different switches or in a switch partitioned to VLANs).

   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
   be incompatible with 82541/82547:

       Planex FXG-08TE
       I-O Data ETG-SH8

   To workaround this issue, the driver can be compiled with an override
   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>

   Where <n> is:

       0 = Hardware default
       1 = Master mode
       2 = Slave mode
       3 = Auto master/slave

   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.

   For example:

      ethtool -A eth? autoneg off rx off


 Support
 =======

 For general information, go to the Intel support website at:

     http://support.intel.com

     or the Intel Wired Networking project hosted by Sourceforge at:

     http://sourceforge.net/projects/e1000

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

	November 15, 2005


	Contents
	========

	- In This Release
	- Identifying Your Adapter
	- Command Line Parameters
	- Speed and Duplex Configuration
	- Additional Configurations
	- Known Issues
	- Support


	In This Release
	===============

	This file describes the Linux* Base Driver for the Intel(R) PRO/1000 Family
	of Adapters. This driver includes support for Itanium(R)2-based systems.

	For questions related to hardware requirements, refer to the documentation
	supplied with your Intel PRO/1000 adapter. All hardware requirements listed
	apply to use with Linux.

	The following features are now available in supported kernels:
	- Native VLANs
	- Channel Bonding (teaming)
	- SNMP

	Channel Bonding documentation can be found in the Linux kernel source:
	/Documentation/networking/bonding.txt

	The driver information previously displayed in the /proc filesystem is not
	supported in this release. Alternatively, you can use ethtool (version 1.6
	or later), lspci, and ifconfig to obtain the same information.

	Instructions on updating ethtool can be found in the section "Additional
	Configurations" later in this document.


	Identifying Your Adapter
	========================

	For more information on how to identify your adapter, go to the Adapter &
	Driver ID Guide at:

	http://support.intel.com/support/network/adapter/pro100/21397.htm

	For the latest Intel network drivers for Linux, refer to the following
	website. In the search field, enter your adapter name or type, or use the
	networking link on the left to search for your adapter:

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


	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:

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

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

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

	insmod e1000 TxDescriptors=80,128

	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.

	NOTES: For more information about the AutoNeg, Duplex, and Speed
	parameters, see the "Speed and Duplex Configuration" section in
	this document.

	For more information about the InterruptThrottleRate,
	RxIntDelay, TxIntDelay, RxAbsIntDelay, and TxAbsIntDelay
	parameters, see the application note at:
	http://www.intel.com/design/network/applnots/ap450.htm

	A descriptor describes a data buffer and attributes related to
	the data buffer. This information is accessed by the hardware.


	AutoNeg
	-------
	(Supported only on adapters with copper connections)
	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.

	NOTE: Refer to the Speed and Duplex section of this readme for more
	information on the AutoNeg parameter.


	Duplex
	------
	(Supported only on adapters with copper connections)
	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.


	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

	This parameter controls the automatic generation(Tx) and response(Rx)
	to Ethernet PAUSE frames.


	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.

	NOTE: InterruptThrottleRate takes precedence over the TxAbsIntDelay and
	RxAbsIntDelay parameters. In other words, minimizing the receive
	and/or transmit absolute delays does not force the controller to
	generate more interrupts than what the Interrupt Throttle Rate
	allows.

	CAUTION: If you are using the Intel 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
	WATCHDOG message is logged in the system event log. In
	addition, the controller is automatically reset, restoring
	the network connection. To eliminate the potential for the
	hang, ensure that InterruptThrottleRate is set no greater
	than 75,000 and is not set to 0.

	NOTE: When e1000 is loaded with default settings and multiple adapters
	are in use simultaneously, the CPU utilization may increase non-
	linearly. In order to limit the CPU utilization without impacting
	the overall throughput, we recommend that you load the driver as
	follows:

	insmod e1000.o InterruptThrottleRate=3000,3000,3000

	This sets the InterruptThrottleRate to 3000 interrupts/sec for
	the first, second, and third instances of the driver. The range
	of 2000 to 3000 interrupts per second works on a majority of
	systems and is a good starting point, but the optimal value will
	be platform-specific. If CPU utilization is not a concern, use
	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.


	RxIntDelay
	----------
	Valid Range: 0-65535 (0=off)
	Default Value: 0

	This value delays the generation of receive interrupts in units of 1.024
	microseconds. Receive interrupt reduction can improve CPU efficiency if
	properly tuned for specific network traffic. Increasing this value adds
	extra latency to frame reception and can end up decreasing the throughput
	of TCP traffic. If the system is reporting dropped receives, this value
	may be set too high, causing the driver to run out of available receive
	descriptors.

	CAUTION: When setting RxIntDelay to a value other than 0, adapters may
	hang (stop transmitting) under certain network conditions. If
	this occurs a NETDEV WATCHDOG message is logged in the system
	event log. In addition, the controller is automatically reset,
	restoring the network connection. To eliminate the potential
	for the hang ensure that RxIntDelay is set to 0.


	RxAbsIntDelay
	-------------
	(This parameter is supported only on 82540, 82545 and later adapters.)
	Valid Range: 0-65535 (0=off)
	Default Value: 128

	This value, in units of 1.024 microseconds, limits the delay in which a
	receive interrupt is generated. Useful only if RxIntDelay is non-zero,
	this value ensures that an interrupt is generated after the initial
	packet is received within the set amount of time. Proper tuning,
	along with RxIntDelay, may improve traffic throughput in specific network
	conditions.


	Speed
	-----
	(This parameter is supported only on adapters with copper connections.)
	Valid Settings: 0, 10, 100, 1000
	Default Value: 0 (auto-negotiate at all supported speeds)

	Speed forces the line speed to the specified value in megabits per second
	(Mbps). If this parameter is not specified or is set to 0 and the link
	partner is set to auto-negotiate, the board will auto-detect the correct
	speed. Duplex should also be set when Speed is set to either 10 or 100.


	TxDescriptors
	-------------
	Valid Range: 80-256 for 82542 and 82543-based adapters
	80-4096 for all other supported adapters
	Default Value: 256

	This value is the number of transmit descriptors allocated by the driver.
	Increasing this value allows the driver to queue more transmits. Each
	descriptor is 16 bytes.

	NOTE: Depending on the available system resources, the request for a
	higher number of transmit descriptors may be denied. In this case,
	use a lower number.


	TxIntDelay
	----------
	Valid Range: 0-65535 (0=off)
	Default Value: 64

	This value delays the generation of transmit interrupts in units of
	1.024 microseconds. Transmit interrupt reduction can improve CPU
	efficiency if properly tuned for specific network traffic. If the
	system is reporting dropped transmits, this value may be set too high
	causing the driver to run out of available transmit descriptors.


	TxAbsIntDelay
	-------------
	(This parameter is supported only on 82540, 82545 and later adapters.)
	Valid Range: 0-65535 (0=off)
	Default Value: 64

	This value, in units of 1.024 microseconds, limits the delay in which a
	transmit interrupt is generated. Useful only if TxIntDelay is non-zero,
	this value ensures that an interrupt is generated after the initial
	packet is sent on the wire within the set amount of time. Proper tuning,
	along with TxIntDelay, may improve traffic throughput in specific
	network conditions.

	XsumRX
	------
	(This parameter is NOT supported on the 82542-based adapter.)
	Valid Range: 0-1
	Default Value: 1

	A value of '1' indicates that the driver should enable IP checksum
	offload for received packets (both UDP and TCP) to the adapter hardware.


	Speed and Duplex Configuration
	==============================

	Three keywords are used to control the speed and duplex configuration.
	These keywords are Speed, Duplex, and AutoNeg.

	If the board uses a fiber interface, these keywords are ignored, and the
	fiber interface board only links at 1000 Mbps full-duplex.

	For copper-based boards, the keywords interact as follows:

	The default operation is auto-negotiate. The board advertises all
	supported speed and duplex combinations, and it links at the highest
	common speed and duplex mode IF the link partner is set to auto-negotiate.

	If Speed = 1000, limited auto-negotiation is enabled and only 1000 Mbps
	is advertised (The 1000BaseT spec requires auto-negotiation.)

	If Speed = 10 or 100, then both Speed and Duplex should be set. Auto-
	negotiation is disabled, and the AutoNeg parameter is ignored. Partner
	SHOULD also be forced.

	The AutoNeg parameter is used when more control is required over the
	auto-negotiation process. It should be used when you wish to control which
	speed and duplex combinations are advertised during the auto-negotiation
	process.

	The parameter may be specified as either a decimal or hexidecimal value as
	determined by the bitmap below.

	Bit position 7 6 5 4 3 2 1 0
	Decimal Value 128 64 32 16 8 4 2 1
	Hex value 80 40 20 10 8 4 2 1
	Speed (Mbps) N/A N/A 1000 N/A 100 100 10 10
	Duplex Full Full Half Full Half

	Some examples of using AutoNeg:

	modprobe e1000 AutoNeg=0x01 (Restricts autonegotiation to 10 Half)
	modprobe e1000 AutoNeg=1 (Same as above)
	modprobe e1000 AutoNeg=0x02 (Restricts autonegotiation to 10 Full)
	modprobe e1000 AutoNeg=0x03 (Restricts autonegotiation to 10 Half or 10 Full)
	modprobe e1000 AutoNeg=0x04 (Restricts autonegotiation to 100 Half)
	modprobe e1000 AutoNeg=0x05 (Restricts autonegotiation to 10 Half or 100
	Half)
	modprobe e1000 AutoNeg=0x020 (Restricts autonegotiation to 1000 Full)
	modprobe e1000 AutoNeg=32 (Same as above)

	Note that when this parameter is used, Speed and Duplex must not be specified.

	If the link partner is forced to a specific speed and duplex, then this
	parameter should not be used. Instead, use the Speed and Duplex parameters
	previously mentioned to force the adapter to the same speed and duplex.


	Additional Configurations
	=========================

	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
	as editing other system startup scripts and/or configuration files. Many
	popular Linux distributions ship with tools to make these changes for you.
	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.

	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 or modprobe.conf:

	alias eth0 e1000
	alias eth1 e1000
	options e1000 Speed=10,100 Duplex=2,1

	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:

	dmesg -n 8

	NOTE: This setting is not saved across reboots.

	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:

	ifconfig eth<x> mtu 9000 up

	This setting is not saved across reboots. It can be made permanent if
	you add:

	MTU=9000

	to the file /etc/sysconfig/network-scripts/ifcfg-eth<x>. This example
	applies to the Red Hat distributions; other distributions may store this
	setting in a different location.

	Notes:

	- 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.


	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.

	The latest release of ethtool can be found from
	http://sourceforge.net/projects/gkernel.

	NOTE: Ethtool 1.6 only supports a limited set of ethtool options. Support
	for a more complete ethtool feature set can be enabled by upgrading
	ethtool to ethtool-1.8.1.

	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:
	http://sourceforge.net/projects/gkernel.

	For instructions on enabling WoL with Ethtool, refer to the website listed
	above.

	WoL will be enabled on the system during the next shut down or reboot.
	For this driver version, in order to enable WoL, the e1000 driver must be
	loaded when shutting down or rebooting the system.

	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.

	To enable NAPI, compile the driver module, passing in a configuration option:

	make CFLAGS_EXTRA=-DE1000_NAPI install

	To disable NAPI, compile the driver module, passing in a configuration option:

	make CFLAGS_EXTRA=-DE1000_NO_NAPI install

	See www.cyberus.ca/~hadi/usenix-paper.tgz for more information on NAPI.


	Known Issues
	============

	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
	requirement of 64 MB of system memory.

	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
	may help. See the specific application manual and
	/usr/src/linux*/Documentation/
	networking/ip-sysctl.txt for more details.

	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.

	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
	will respond to IP traffic for any IP address assigned to the system.
	This results in unbalanced receive traffic.

	If you have multiple interfaces in a server, either turn on ARP
	filtering by entering:

	echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter
	(this only works if your kernel's version is higher than 2.4.5),

	NOTE: This setting is not saved across reboots. The configuration
	change can be made permanent by adding the line:
	net.ipv4.conf.all.arp_filter = 1
	to the file /etc/sysctl.conf

	or,

	install the interfaces in separate broadcast domains (either in
	different switches or in a switch partitioned to VLANs).

	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
	be incompatible with 82541/82547:

	Planex FXG-08TE
	I-O Data ETG-SH8

	To workaround this issue, the driver can be compiled with an override
	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>

	Where <n> is:

	0 = Hardware default
	1 = Master mode
	2 = Slave mode
	3 = Auto master/slave

	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.

	For example:

	ethtool -A eth? autoneg off rx off


	Support
	=======

	For general information, go to the Intel support website at:

	http://support.intel.com

	or the Intel Wired Networking project hosted by Sourceforge at:

	http://sourceforge.net/projects/e1000

	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.