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-rw-r--r--Documentation/networking/e1000.rst149
1 files changed, 94 insertions, 55 deletions
diff --git a/Documentation/networking/e1000.rst b/Documentation/networking/e1000.rst
index 616848940e63..f10dd4086921 100644
--- a/Documentation/networking/e1000.rst
+++ b/Documentation/networking/e1000.rst
@@ -1,3 +1,4 @@
+===========================================================
Linux* Base Driver for Intel(R) Ethernet Network Connection
===========================================================
@@ -33,7 +34,8 @@ 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
+NOTES:
+ For more information about the AutoNeg, Duplex, and Speed
parameters, see the "Speed and Duplex Configuration" section in
this document.
@@ -44,22 +46,27 @@ NOTES: For more information about the AutoNeg, Duplex, and Speed
AutoNeg
-------
+
(Supported only on adapters with copper connections)
-Valid Range: 0x01-0x0F, 0x20-0x2F
-Default Value: 0x2F
+
+: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
+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
+
+: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
@@ -69,18 +76,22 @@ 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
+
+: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
+
+: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
@@ -134,13 +145,15 @@ 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
+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
+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
@@ -150,7 +163,8 @@ CAUTION: If you are using the Intel(R) PRO/1000 CT Network Connection
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
+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
@@ -167,9 +181,11 @@ NOTE: When e1000 is loaded with default settings and multiple adapters
RxDescriptors
-------------
-Valid Range: 48-256 for 82542 and 82543-based adapters
- 48-4096 for all other supported adapters
-Default Value: 256
+
+:Valid Range:
+ - 48-256 for 82542 and 82543-based adapters
+ - 48-4096 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
@@ -179,15 +195,17 @@ 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
+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
+
+: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
@@ -197,7 +215,8 @@ 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
+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,
@@ -206,9 +225,11 @@ CAUTION: When setting RxIntDelay to a value other than 0, adapters may
RxAbsIntDelay
-------------
+
(This parameter is supported only on 82540, 82545 and later adapters.)
-Valid Range: 0-65535 (0=off)
-Default Value: 128
+
+: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,
@@ -219,9 +240,11 @@ 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)
+
+: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
@@ -230,22 +253,26 @@ speed. Duplex should also be set when Speed is set to either 10 or 100.
TxDescriptors
-------------
-Valid Range: 48-256 for 82542 and 82543-based adapters
- 48-4096 for all other supported adapters
-Default Value: 256
+
+:Valid Range:
+ - 48-256 for 82542 and 82543-based adapters
+ - 48-4096 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
+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: 8
+
+: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
@@ -255,9 +282,11 @@ 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: 32
+
+: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,
@@ -268,18 +297,21 @@ network conditions.
XsumRX
------
+
(This parameter is NOT supported on the 82542-based adapter.)
-Valid Range: 0-1
-Default Value: 1
+
+: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: modprobe e1000.ko copybreak=128
+
+:Valid Range: 0-xxxxxxx (0=off)
+:Default Value: 256
+:Usage: modprobe e1000.ko copybreak=128
Driver copies all packets below or equaling this size to a fresh RX
buffer before handing it up the stack.
@@ -291,8 +323,9 @@ it is also available during runtime at
SmartPowerDownEnable
--------------------
-Valid Range: 0-1
-Default Value: 0 (disabled)
+
+: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.
@@ -308,14 +341,14 @@ 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
+- 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
+- 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-
+- 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.
@@ -327,13 +360,15 @@ 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:
+Some examples of using AutoNeg::
modprobe e1000 AutoNeg=0x01 (Restricts autonegotiation to 10 Half)
modprobe e1000 AutoNeg=1 (Same as above)
@@ -354,8 +389,9 @@ previously mentioned to force the adapter to the same speed and duplex.
Additional Configurations
=========================
- Jumbo Frames
- ------------
+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::
@@ -367,11 +403,11 @@ Additional Configurations
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.
+ 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:
+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.
@@ -385,12 +421,14 @@ Additional Configurations
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:
+ 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
- -------
+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.
@@ -398,8 +436,9 @@ Additional Configurations
The latest release of ethtool can be found from
https://www.kernel.org/pub/software/network/ethtool/
- Enabling Wake on LAN* (WoL)
- ---------------------------
+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.