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Intel 82546系列lan driver源码

Linux* Base Driver for Intel(R) Network Connection
===============================================================

November 21, 2008

Contents
========

- In This Release
- Identifying Your Adapter
- Upgrading
- Building and Installation
- Command Line Parameters
- Additional Configurations
- Known Issues/Troubleshooting
- Support


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

This file describes the e1000e Linux* Base Driver for Intel Network Connection.  
This driver supports kernel versions 2.4.x and 2.6.x.  This driver includes 
support for Itanium(R)2-based systems.

NOTE: The 82546GB part requires the e1000 driver, not the e1000e driver.
 
This driver is only supported as a loadable module at this time.  Intel is
not supplying patches against the kernel source to allow for static linking
of the driver.  For questions related to hardware requirements, refer to the
documentation supplied with your Intel Gigabit adapter.  All hardware
requirements listed apply to use with Linux.

This release includes support for Intel(R) I/O Acceleration Technology,
Intel(R) I/OAT. You can find additional information on Intel I/OAT at 
http://www.intel.com/technology/ioacceleration/index.htm.

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.

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


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/go/network/adapter/idguide.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://downloadcenter.intel.com/scripts-df-external/Support_Intel.aspx

Upgrading
=========

If you currently have the e1000 driver installed and need to install e1000e,
perform the following:

 - If your version of e1000 is 7.6.15.5 or less, upgrade to e1000 version 8.x,
   using the instructions in the e1000 README. 
 - Install the e1000e driver using the instructions in the Building and 
   Installation section below.
 - Modify /etc/modprobe.conf to point your PCIe devices to use the new e1000e 
   driver using alias ethX e1000e, or use your distribution's specific method 
   for configuring network adapters like RedHat's setup/system-config-network
   or SuSE's yast2.

Building and Installation
=========================

To build a binary RPM* package of this driver, run 'rpmbuild -tb
<filename.tar.gz>'.  Replace <filename.tar.gz> with the specific filename
of the driver.

NOTE: For the build to work properly, the currently running kernel MUST
      match the version and configuration of the installed kernel sources.
      If you have just recompiled the kernel reboot the system now.

      RPM functionality has only been tested in Red Hat distributions.

1. Move the base driver tar file to the directory of your choice.  For
   example, use /home/username/e1000e or /usr/local/src/e1000e.

2. Untar/unzip archive:

     tar zxf e1000e-x.x.x.tar.gz

3. Change to the driver src directory:

     cd e1000e-x.x.x/src/

4. Compile the driver module:

     # make install

   The binary will be installed as:

     /lib/modules/<KERNEL VERSION>/kernel/drivers/net/e1000e/e1000e.[k]o

   The install locations listed above are the default locations.  They
   might not be correct for certain Linux distributions. 

5. Load the module using either the insmod or modprobe command:

     modprobe e1000e

     insmod e1000e

   Note that for 2.6 kernels the insmod command can be used if the full
   path to the driver module is specified.  For example:

     insmod /lib/modules/<KERNEL VERSION>/kernel/drivers/net/e1000e/e1000e.ko

   With 2.6 based kernels also make sure that older e1000e drivers are 
   removed from the kernel, before loading the new module:

     rmmod e1000e; modprobe e1000e


6. Assign an IP address to the interface by entering the following, where
   x is the interface number:

     ifconfig ethx <IP_address>

7. Verify that the interface works.  Enter the following, where <IP_address>
   is the IP address for another machine on the same subnet as the
   interface that is being tested:

     ping  <IP_address>

TROUBLESHOOTING: Some systems have trouble supporting MSI and/or MSI-X 
interrupts.  If you believe your system needs to disable this style of 
interrupt, the driver can be built and installed with the command:

     # make CFLAGS_EXTRA=-DDISABLE_PCI_MSI install

Normally the driver will generate an interrupt every two seconds, so if
you can see that you're no longer getting interrupts in
cat /proc/interrupts for the ethX e1000e device, then this workaround
may be necessary.
	

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 command
using this syntax:

     modprobe e1000e [<option>=<VAL1>,<VAL2>,...]

The default value for each parameter is generally the recommended setting,
unless otherwise noted.

NOTES:  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.


InterruptThrottleRate
---------------------
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
       and/or transmit absolute delays does not force the controller to
       generate more interrupts than what the Interrupt Throttle Rate
       allows.

NOTE:  When e1000e 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:

           modprobe e1000e 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.


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
-------------
Valid Range:   0-65535 (0=off)
Default Value: 8

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.


TxIntDelay
----------
Valid Range:   0-65535 (0=off)
Default Value: 8

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
-------------
Valid Range:   0-65535 (0=off)
Default Value: 32

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.


Copybreak
---------
Valid Range:   0-xxxxxxx (0=off)
Default Value: 256
Usage: insmod e1000e.ko copybreak=128

Driver copies all packets below or equaling this size to a fresh rx
buffer before handing it up the stack.

This parameter is different than other parameters, in that it is a
single (not 1,1,1 etc.) parameter applied to all driver instances and
it is also available during runtime at 
/sys/module/e1000e/parameters/copybreak


SmartPowerDownEnable
--------------------
Valid Range: 0-1
Default Value:  0 (disabled)

Allows Phy to turn off in lower power states. The user can turn off
this parameter in supported chipsets.


KumeranLockLoss
---------------
Valid Range: 0-1
Default Value: 1 (enabled)

This workaround skips resetting the Phy at shutdown for the initial
silicon releases of ICH8 systems.


IntMode
-------
Valid Range: 0-2
Default Value: 2 
(0=legacy, 1=MSI, 2=MSI-X)

Allows changing the interrupt mode at module load time, without requiring a
recompile. If the driver load fails to enable a specific interrupt mode, the
driver will try other interrupt modes, from least to most compatible.  The 
interrupt order is MSI-X, MSI, Legacy.  If specifying MSI (IntMode=1) 
interrupts, only MSI and Legacy will be attempted.


WriteProtectNVM
---------------
Valid Range:   0-1
Default Value: 1 (enabled)

This option is applicable only on ICHx (8256x) parts.  By default, the NVM is
write-protected in order to prevent malicious accesses of the mapped NVM 
control register space which could potentially corrupt the NVM resulting in