Documentation/networking/e1000.txt

   1 Linux* Base Driver for the Intel(R) PRO/1000 Family of Adapters
   2 ===============================================================
   3
   4 November 17, 2004
   5
   6
   7 Contents
   8 ========
   9
  10 - In This Release
  11 - Identifying Your Adapter
  12 - Command Line Parameters
  13 - Speed and Duplex Configuration
  14 - Additional Configurations
  15 - Known Issues
  16 - Support
  17
  18
  19 In This Release
  20 ===============
  21
  22 This file describes the Linux* Base Driver for the Intel(R) PRO/1000 Family
  23 of Adapters, version 5.x.x.
  24
  25 For questions related to hardware requirements, refer to the documentation
  26 supplied with your Intel PRO/1000 adapter. All hardware requirements listed
  27 apply to use with Linux.
  28
  29 Native VLANs are now available with supported kernels.
  30
  31 Identifying Your Adapter
  32 ========================
  33
  34 For more information on how to identify your adapter, go to the Adapter &
  35 Driver ID Guide at:
  36
  37     http://support.intel.com/support/network/adapter/pro100/21397.htm
  38
  39 For the latest Intel network drivers for Linux, refer to the following
  40 website. In the search field, enter your adapter name or type, or use the
  41 networking link on the left to search for your adapter:
  42
  43     http://downloadfinder.intel.com/scripts-df/support_intel.asp
  44
  45 Command Line Parameters
  46 =======================
  47
  48 If the driver is built as a module, the  following optional parameters are
  49 used by entering them on the command line with the modprobe or insmod command
  50 using this syntax:
  51
  52      modprobe e1000 [<option>=<VAL1>,<VAL2>,...]
  53
  54      insmod e1000 [<option>=<VAL1>,<VAL2>,...]
  55
  56 For example, with two PRO/1000 PCI adapters, entering:
  57
  58      insmod e1000 TxDescriptors=80,128
  59
  60 loads the e1000 driver with 80 TX descriptors for the first adapter and 128 TX
  61 descriptors for the second adapter.
  62
  63 The default value for each parameter is generally the recommended setting,
  64 unless otherwise noted. Also, if the driver is statically built into the
  65 kernel, the driver is loaded with the default values for all the parameters.
  66 Ethtool can be used to change some of the parameters at runtime.
  67
  68     NOTES: For more information about the AutoNeg, Duplex, and Speed
  69            parameters, see the "Speed and Duplex Configuration" section in
  70            this document.
  71
  72            For more information about the InterruptThrottleRate, RxIntDelay,
  73            TxIntDelay, RxAbsIntDelay, and TxAbsIntDelay parameters, see the
  74            application note at:
  75            http://www.intel.com/design/network/applnots/ap450.htm
  76
  77            A descriptor describes a data buffer and attributes related to the
  78            data buffer. This information is accessed by the hardware.
  79
  80 AutoNeg (adapters using copper connections only)
  81 Valid Range: 0x01-0x0F, 0x20-0x2F
  82 Default Value: 0x2F
  83     This parameter is a bit mask that specifies which speed and duplex
  84     settings the board advertises. When this parameter is used, the Speed and
  85     Duplex parameters must not be specified.
  86     NOTE: Refer to the Speed and Duplex section of this readme for more
  87           information on the AutoNeg parameter.
  88
  89 Duplex (adapters using copper connections only)
  90 Valid Range: 0-2 (0=auto-negotiate, 1=half, 2=full)
  91 Default Value: 0
  92     Defines the direction in which data is allowed to flow. Can be either one
  93     or two-directional. If both Duplex and the link partner are set to auto-
  94     negotiate, the board auto-detects the correct duplex. If the link partner
  95     is forced (either full or half), Duplex defaults to half-duplex.
  96
  97 FlowControl
  98 Valid Range: 0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx)
  99 Default: Read flow control settings from the EEPROM
 100     This parameter controls the automatic generation(Tx) and response(Rx) to
 101     Ethernet PAUSE frames.
 102
 103 InterruptThrottleRate
 104 Valid Range: 100-100000 (0=off, 1=dynamic)
 105 Default Value: 8000
 106     This value represents the maximum number of interrupts per second the
 107     controller generates. InterruptThrottleRate is another setting used in
 108     interrupt moderation. Dynamic mode uses a heuristic algorithm to adjust
 109     InterruptThrottleRate based on the current traffic load.
 110 Un-supported Adapters: InterruptThrottleRate is NOT supported by 82542, 82543
 111     or 82544-based adapters.
 112
 113     NOTE: InterruptThrottleRate takes precedence over the TxAbsIntDelay and
 114           RxAbsIntDelay parameters. In other words, minimizing the receive
 115           and/or transmit absolute delays does not force the controller to
 116           generate more interrupts than what the Interrupt Throttle Rate
 117           allows.
 118     CAUTION: If you are using the Intel PRO/1000 CT Network Connection
 119              (controller 82547), setting InterruptThrottleRate to a value
 120              greater than 75,000, may hang (stop transmitting) adapters under
 121              certain network conditions. If this occurs a NETDEV WATCHDOG
 122              message is logged in the system event log. In addition, the
 123              controller is automatically reset, restoring the network
 124              connection. To eliminate the potential for the hang, ensure
 125              that InterruptThrottleRate is set no greater than 75,000 and is
 126              not set to 0.
 127     NOTE: When e1000 is loaded with default settings and multiple adapters are
 128           in use simultaneously, the CPU utilization may increase non-linearly.
 129           In order to limit the CPU utilization without impacting the overall
 130           throughput, we recommend that you load the driver as follows:
 131
 132               insmod e1000.o InterruptThrottleRate=3000,3000,3000
 133
 134           This sets the InterruptThrottleRate to 3000 interrupts/sec for the
 135           first, second, and third instances of the driver. The range of 2000 to
 136           3000 interrupts per second works on a majority of systems and is a
 137           good starting point, but the optimal value will be platform-specific.
 138           If CPU utilization is not a concern, use RX_POLLING (NAPI) and default
 139           driver settings.
 140
 141 RxDescriptors
 142 Valid Range: 80-256 for 82542 and 82543-based adapters
 143              80-4096 for all other supported adapters
 144 Default Value: 256
 145     This value is the number of receive descriptors allocated by the driver.
 146     Increasing this value allows the driver to buffer more incoming packets.
 147     Each descriptor is 16 bytes.  A receive buffer is allocated for each
 148     descriptor and can either be 2048 or 4096 bytes long, depending on the MTU
 149
 150     setting. An incoming packet can span one or more receive descriptors.
 151     The maximum MTU size is 16110.
 152
 153     NOTE: MTU designates the frame size. It only needs to be set for Jumbo
 154           Frames.
 155     NOTE: Depending on the available system resources, the request for a
 156     higher number of receive descriptors may be denied.  In this case,
 157     use a lower number.
 158
 159 RxIntDelay
 160 Valid Range: 0-65535 (0=off)
 161 Default Value: 0
 162     This value delays the generation of receive interrupts in units of 1.024
 163     microseconds.  Receive interrupt reduction can improve CPU efficiency if
 164     properly tuned for specific network traffic. Increasing this value adds
 165     extra latency to frame reception and can end up decreasing the throughput
 166     of TCP traffic. If the system is reporting dropped receives, this value
 167     may be set too high, causing the driver to run out of available receive
 168     descriptors.
 169
 170     CAUTION: When setting RxIntDelay to a value other than 0, adapters may
 171              hang (stop transmitting) under certain network conditions. If
 172              this occurs a NETDEV WATCHDOG message is logged in the system
 173              event log. In addition, the controller is automatically reset,
 174              restoring the network connection. To eliminate the potential for
 175              the hang ensure that RxIntDelay is set to 0.
 176
 177 RxAbsIntDelay (82540, 82545 and later adapters only)
 178 Valid Range: 0-65535 (0=off)
 179 Default Value: 128
 180     This value, in units of 1.024 microseconds, limits the delay in which a
 181     receive interrupt is generated. Useful only if RxIntDelay is non-zero,
 182     this value ensures that an interrupt is generated after the initial
 183     packet is received within the set amount of time.  Proper tuning,
 184     along with RxIntDelay, may improve traffic throughput in specific network
 185     conditions.
 186
 187 Speed (adapters using copper connections only)
 188 Valid Settings: 0, 10, 100, 1000
 189 Default Value: 0 (auto-negotiate at all supported speeds)
 190     Speed forces the line speed to the specified value in megabits per second
 191     (Mbps). If this parameter is not specified or is set to 0 and the link
 192     partner is set to auto-negotiate, the board will auto-detect the correct
 193     speed. Duplex should also be set when Speed is set to either 10 or 100.
 194
 195 TxDescriptors
 196 Valid Range: 80-256 for 82542 and 82543-based adapters
 197              80-4096 for all other supported adapters
 198 Default Value: 256
 199     This value is the number of transmit descriptors allocated by the driver.
 200     Increasing this value allows the driver to queue more transmits. Each
 201     descriptor is 16 bytes.
 202
 203     NOTE: Depending on the available system resources, the request for a
 204     higher number of transmit descriptors may be denied.  In this case,
 205     use a lower number.
 206
 207 TxIntDelay
 208 Valid Range: 0-65535 (0=off)
 209 Default Value: 64
 210     This value delays the generation of transmit interrupts in units of
 211     1.024 microseconds. Transmit interrupt reduction can improve CPU
 212     efficiency if properly tuned for specific network traffic. If the
 213     system is reporting dropped transmits, this value may be set too high
 214     causing the driver to run out of available transmit descriptors.
 215
 216 TxAbsIntDelay (82540, 82545 and later adapters only)
 217 Valid Range: 0-65535 (0=off)
 218 Default Value: 64
 219     This value, in units of 1.024 microseconds, limits the delay in which a
 220     transmit interrupt is generated. Useful only if TxIntDelay is non-zero,
 221     this value ensures that an interrupt is generated after the initial
 222     packet is sent on the wire within the set amount of time.  Proper tuning,
 223     along with TxIntDelay, may improve traffic throughput in specific
 224     network conditions.
 225
 226 XsumRX (not available on the 82542-based adapter)
 227 Valid Range: 0-1
 228 Default Value: 1
 229     A value of '1' indicates that the driver should enable IP checksum
 230     offload for received packets (both UDP and TCP) to the adapter hardware.
 231
 232 Speed and Duplex Configuration
 233 ==============================
 234
 235 Three keywords are used to control the speed and duplex configuration. These
 236 keywords are Speed, Duplex, and AutoNeg.
 237
 238 If the board uses a fiber interface, these keywords are ignored, and the
 239 fiber interface board only links at 1000 Mbps full-duplex.
 240
 241 For copper-based boards, the keywords interact as follows:
 242
 243   The default operation is auto-negotiate. The board advertises all supported
 244   speed and duplex combinations, and it links at the highest common speed and
 245   duplex mode IF the link partner is set to auto-negotiate.
 246
 247   If Speed = 1000, limited auto-negotiation is enabled and only 1000 Mbps is
 248   advertised (The 1000BaseT spec requires auto-negotiation.)
 249
 250   If Speed = 10 or 100, then both Speed and Duplex should be set. Auto-
 251   negotiation is disabled, and the AutoNeg parameter is ignored. Partner SHOULD
 252   also be forced.
 253
 254 The AutoNeg parameter is used when more control is required over the auto-
 255 negotiation process. When this parameter is used, Speed and Duplex parameters
 256 must not be specified. The following table describes supported values for the
 257 AutoNeg parameter:
 258
 259 Speed (Mbps)             1000      100    100    10     10
 260 Duplex                   Full      Full   Half   Full   Half
 261 Value (in base 16)       0x20      0x08   0x04   0x02   0x01
 262
 263 Example: insmod e1000 AutoNeg=0x03, loads e1000 and specifies (10 full duplex,
 264 10 half duplex) for negotiation with the peer.
 265
 266 Note that setting AutoNeg does not guarantee that the board will link at the
 267 highest specified speed or duplex mode, but the board will link at the
 268 highest possible speed/duplex of the link partner IF the link partner is also
 269 set to auto-negotiate. If the link partner is forced speed/duplex, the
 270 adapter MUST be forced to the same speed/duplex.
 271
 272
 273 Additional Configurations
 274 =========================
 275
 276   Configuring the Driver on Different Distributions
 277   -------------------------------------------------
 278
 279   Configuring a network driver to load properly when the system is started is
 280   distribution dependent. Typically, the configuration process involves adding
 281   an alias line to /etc/modules.conf as well as editing other system startup
 282   scripts and/or configuration files. Many popular Linux distributions ship
 283   with tools to make these changes for you. To learn the proper way to
 284   configure a network device for your system, refer to your distribution
 285   documentation. If during this process you are asked for the driver or module
 286   name, the name for the Linux Base Driver for the Intel PRO/1000 Family of
 287   Adapters is e1000.
 288
 289   As an example, if you install the e1000 driver for two PRO/1000 adapters
 290   (eth0 and eth1) and set the speed and duplex to 10full and 100half, add the
 291   following to modules.conf:
 292
 293        alias eth0 e1000
 294        alias eth1 e1000
 295        options e1000 Speed=10,100 Duplex=2,1
 296
 297   Viewing Link Messages
 298   ---------------------
 299
 300   Link messages will not be displayed to the console if the distribution is
 301   restricting system messages. In order to see network driver link messages on
 302   your console, set dmesg to eight by entering the following:
 303
 304        dmesg -n 8
 305
 306   NOTE: This setting is not saved across reboots.
 307
 308   Jumbo Frames
 309   ------------
 310
 311   The driver supports Jumbo Frames for all adapters except 82542-based
 312   adapters. Jumbo Frames support is enabled by changing the MTU to a value
 313   larger than the default of 1500. Use the ifconfig command to increase the
 314   MTU size. For example:
 315
 316         ifconfig ethx mtu 9000 up
 317
 318   The maximum MTU setting for Jumbo Frames is 16110. This value coincides
 319   with the maximum Jumbo Frames size of 16128.
 320
 321   NOTE: Jumbo Frames are supported at 1000 Mbps only. Using Jumbo Frames at
 322   10 or 100 Mbps may result in poor performance or loss of link.
 323
 324
 325   NOTE: MTU designates the frame size. To enable Jumbo Frames, increase the
 326   MTU size on the interface beyond 1500.
 327
 328   Ethtool
 329   -------
 330
 331   The driver utilizes the ethtool interface for driver configuration and
 332   diagnostics, as well as displaying statistical information.  Ethtool
 333   version 1.6 or later is required for this functionality.
 334
 335   The latest release of ethtool can be found from
 336   http://sf.net/projects/gkernel.
 337
 338   NOTE: Ethtool 1.6 only supports a limited set of ethtool options. Support
 339   for a more complete ethtool feature set can be enabled by upgrading
 340   ethtool to ethtool-1.8.1.
 341
 342   Enabling Wake on LAN* (WoL)
 343   ---------------------------
 344
 345   WoL is configured through the Ethtool* utility. Ethtool is included with
 346   all versions of Red Hat after Red Hat 7.2. For other Linux distributions,
 347   download and install Ethtool from the following website:
 348   http://sourceforge.net/projects/gkernel.
 349
 350   For instructions on enabling WoL with Ethtool, refer to the website listed
 351   above.
 352
 353   WoL will be enabled on the system during the next shut down or reboot.
 354   For this driver version, in order to enable WoL, the e1000 driver must be
 355   loaded when shutting down or rebooting the system.
 356
 357   NAPI
 358   ----
 359
 360   NAPI (Rx polling mode) is supported in the e1000 driver. NAPI is enabled
 361   or disabled based on the configuration of the kernel.
 362
 363   See www.cyberus.ca/~hadi/usenix-paper.tgz for more information on NAPI.
 364
 365
 366 Known Issues
 367 ============
 368
 369   Jumbo Frames System Requirement
 370   -------------------------------
 371
 372   Memory allocation failures have been observed on Linux systems with 64 MB
 373   of RAM or less that are running Jumbo Frames. If you are using Jumbo Frames,
 374   your system may require more than the advertised minimum requirement of 64 MB
 375   of system memory.
 376
 377
 378 Support
 379 =======
 380
 381 For general information, go to the Intel support website at:
 382
 383     http://support.intel.com
 384
 385 If an issue is identified with the released source code on the supported
 386 kernel with a supported adapter, email the specific information related to
 387 the issue to linux.nics@intel.com.
 388
 389
 390 License
 391 =======
 392
 393 This software program is released under the terms of a license agreement
 394 between you ('Licensee') and Intel. Do not use or load this software or any
 395 associated materials (collectively, the 'Software') until you have carefully
 396 read the full terms and conditions of the LICENSE located in this software
 397 package. By loading or using the Software, you agree to the terms of this
 398 Agreement. If you do not agree with the terms of this Agreement, do not
 399 install or use the Software.
 400
 401 * Other names and brands may be claimed as the property of others.