mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![SeongJae Park](/assets/img/avatar_default.png)
As ftp.kernel.org is closed [0], this commit fixes dead URLs in documents to use www.kernel.org instead. [0] https://www.kernel.org/shutting-down-ftp-services.html Signed-off-by: SeongJae Park <sj38.park@gmail.com> Acked-by: Theodore Ts'o <tytso@mit.edu> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
461 lines
18 KiB
Text
461 lines
18 KiB
Text
Linux* Base Driver for Intel(R) Ethernet Network Connection
|
|
===========================================================
|
|
|
|
Intel Gigabit Linux driver.
|
|
Copyright(c) 1999 - 2013 Intel Corporation.
|
|
|
|
Contents
|
|
========
|
|
|
|
- Identifying Your Adapter
|
|
- Command Line Parameters
|
|
- Speed and Duplex Configuration
|
|
- Additional Configurations
|
|
- 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://support.intel.com/support/go/network/adapter/home.htm
|
|
|
|
Command Line Parameters
|
|
=======================
|
|
|
|
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
|
|
|
|
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 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.
|
|
|
|
Duplex
|
|
------
|
|
(Supported only on adapters with copper connections)
|
|
Valid Range: 0-2 (0=auto-negotiate, 1=half, 2=full)
|
|
Default Value: 0
|
|
|
|
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
|
|
|
|
This parameter controls the automatic generation(Tx) and response(Rx)
|
|
to Ethernet PAUSE frames.
|
|
|
|
InterruptThrottleRate
|
|
---------------------
|
|
(not supported on Intel(R) 82542, 82543 or 82544-based adapters)
|
|
Valid Range: 0,1,3,4,100-100000 (0=off, 1=dynamic, 3=dynamic conservative,
|
|
4=simplified balancing)
|
|
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".
|
|
|
|
In simplified mode the interrupt rate is based on the ratio of TX and
|
|
RX traffic. If the bytes per second rate is approximately equal, the
|
|
interrupt rate will drop as low as 2000 interrupts per second. If the
|
|
traffic is mostly transmit or mostly receive, the interrupt rate could
|
|
be as high as 8000.
|
|
|
|
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.
|
|
|
|
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
|
|
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:
|
|
|
|
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
|
|
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 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
|
|
----------
|
|
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.
|
|
|
|
TxDescriptorStep
|
|
----------------
|
|
Valid Range: 1 (use every Tx Descriptor)
|
|
4 (use every 4th Tx Descriptor)
|
|
|
|
Default Value: 1 (use every Tx Descriptor)
|
|
|
|
On certain non-Intel architectures, it has been observed that intense TX
|
|
traffic bursts of short packets may result in an improper descriptor
|
|
writeback. If this occurs, the driver will report a "TX Timeout" and reset
|
|
the adapter, after which the transmit flow will restart, though data may
|
|
have stalled for as much as 10 seconds before it resumes.
|
|
|
|
The improper writeback does not occur on the first descriptor in a system
|
|
memory cache-line, which is typically 32 bytes, or 4 descriptors long.
|
|
|
|
Setting TxDescriptorStep to a value of 4 will ensure that all TX descriptors
|
|
are aligned to the start of a system memory cache line, and so this problem
|
|
will not occur.
|
|
|
|
NOTES: Setting TxDescriptorStep to 4 effectively reduces the number of
|
|
TxDescriptors available for transmits to 1/4 of the normal allocation.
|
|
This has a possible negative performance impact, which may be
|
|
compensated for by allocating more descriptors using the TxDescriptors
|
|
module parameter.
|
|
|
|
There are other conditions which may result in "TX Timeout", which will
|
|
not be resolved by the use of the TxDescriptorStep parameter. As the
|
|
issue addressed by this parameter has never been observed on Intel
|
|
Architecture platforms, it should not be used on Intel platforms.
|
|
|
|
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.
|
|
|
|
Copybreak
|
|
---------
|
|
Valid Range: 0-xxxxxxx (0=off)
|
|
Default Value: 256
|
|
Usage: insmod e1000.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/e1000/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.
|
|
|
|
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 hexadecimal 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
|
|
=========================
|
|
|
|
Jumbo Frames
|
|
------------
|
|
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:
|
|
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.
|
|
|
|
- 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 is not supported and may result in
|
|
poor performance or loss of link.
|
|
|
|
- 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
|
|
|
|
ethtool
|
|
-------
|
|
The driver utilizes the ethtool interface for driver configuration and
|
|
diagnostics, as well as displaying statistical information. The ethtool
|
|
version 1.6 or later is required for this functionality.
|
|
|
|
The latest release of ethtool can be found from
|
|
https://www.kernel.org/pub/software/network/ethtool/
|
|
|
|
Enabling Wake on LAN* (WoL)
|
|
---------------------------
|
|
WoL is configured through the ethtool* utility.
|
|
|
|
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.
|
|
|
|
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.sf.net
|