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diff --git a/Documentation/networking/e1000.txt b/Documentation/networking/e1000.txt new file mode 100644 index 0000000..2df7186 --- /dev/null +++ b/Documentation/networking/e1000.txt @@ -0,0 +1,642 @@ +Linux* Base Driver for the Intel(R) PRO/1000 Family of Adapters +=============================================================== + +September 26, 2006 + + +Contents +======== + +- In This Release +- Identifying Your Adapter +- Building and Installation +- 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. + +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/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 command +using this syntax: + + modprobe e1000 [<option>=<VAL1>,<VAL2>,...] + +For example, with two PRO/1000 PCI adapters, entering: + + modprobe 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 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: 0,1,3,100-100000 (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. + +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. + + +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 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 +========================= + + 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(R) 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 + ------------ + 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(R) 82571EB, + 82572EI, 82573L and 80003ES2LAN controller. These correspond to the + following product names: + Intel(R) PRO/1000 PT Server Adapter + Intel(R) PRO/1000 PT Desktop Adapter + Intel(R) PRO/1000 PT Network Connection + Intel(R) PRO/1000 PT Dual Port Server Adapter + Intel(R) PRO/1000 PT Dual Port Network Connection + Intel(R) PRO/1000 PF Server Adapter + Intel(R) PRO/1000 PF Network Connection + Intel(R) PRO/1000 PF Dual Port Server Adapter + Intel(R) PRO/1000 PB Server Connection + Intel(R) PRO/1000 PL Network Connection + Intel(R) PRO/1000 EB Network Connection with I/O Acceleration + Intel(R) PRO/1000 EB Backplane Connection with I/O Acceleration + Intel(R) PRO/1000 PT Quad Port Server Adapter + + - 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 + + - The following adapters do not support Jumbo Frames: + Intel(R) 82562V 10/100 Network Connection + Intel(R) 82566DM Gigabit Network Connection + Intel(R) 82566DC Gigabit Network Connection + Intel(R) 82566MM Gigabit Network Connection + Intel(R) 82566MC Gigabit Network Connection + Intel(R) 82562GT 10/100 Network Connection + Intel(R) 82562G 10/100 Network Connection + + + 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. + + Wake On LAN is only supported on port A for the following devices: + Intel(R) PRO/1000 PT Dual Port Network Connection + Intel(R) PRO/1000 PT Dual Port Server Connection + Intel(R) PRO/1000 PT Dual Port Server Adapter + Intel(R) PRO/1000 PF Dual Port Server Adapter + Intel(R) PRO/1000 PT Quad Port Server Adapter + + NAPI + ---- + NAPI (Rx polling mode) is enabled in the e1000 driver. + + See www.cyberus.ca/~hadi/usenix-paper.tgz for more information on NAPI. + + +Known Issues +============ + +Dropped Receive Packets on Half-duplex 10/100 Networks +------------------------------------------------------ +If you have an Intel PCI Express adapter running at 10mbps or 100mbps, half- +duplex, you may observe occasional dropped receive packets. There are no +workarounds for this problem in this network configuration. The network must +be updated to operate in full-duplex, and/or 1000mbps only. + +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. + +Allocating Rx Buffers when Using Jumbo Frames +--------------------------------------------- +Allocating Rx buffers when using Jumbo Frames on 2.6.x kernels may fail if +the available memory is heavily fragmented. This issue may be seen with PCI-X +adapters or with packet split disabled. This can be reduced or eliminated +by changing the amount of available memory for receive buffer allocation, by +increasing /proc/sys/vm/min_free_kbytes. + +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 CFLAGS_EXTRA=-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 + +Unplugging network cable while ethtool -p is running +---------------------------------------------------- +In kernel versions 2.5.50 and later (including 2.6 kernel), unplugging +the network cable while ethtool -p is running will cause the system to +become unresponsive to keyboard commands, except for control-alt-delete. +Restarting the system appears to be the only remedy. + + +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 |
