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Diffstat (limited to 'Documentation/networking/e1000.rst')
| -rw-r--r-- | Documentation/networking/e1000.rst | 149 |
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. |