[PATCH 1/2] igb.txt: Add igb documentation
From: Jeff Kirsher
Date: Tue Aug 03 2010 - 20:22:10 EST
Add documentation for the igb networking driver.
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Tested-by: Jeff Pieper <jeffrey.e.pieper@xxxxxxxxx>
Documentation/networking/igb.txt | 134 ++++++++++++++++++++++++++++++++++++++
1 files changed, 134 insertions(+), 0 deletions(-)
create mode 100644 Documentation/networking/igb.txt
diff --git a/Documentation/networking/igb.txt b/Documentation/networking/igb.txt
new file mode 100644
@@ -0,0 +1,134 @@
+Linux* Base Driver for Intel(R) Network Connection
+Intel Gigabit Linux driver.
+Copyright(c) 1999 - 2010 Intel Corporation.
+- Identifying Your Adapter
+- Additional Configurations
+Identifying Your Adapter
+This driver supports all 82575, 82576 and 82580-based Intel (R) gigabit network
+For specific information on how to identify your adapter, go to the Adapter &
+Driver ID Guide at:
+Command Line Parameters
+The default value for each parameter is generally the recommended setting,
+unless otherwise noted.
+Valid Range: 0-7
+Default Value: 0
+This parameter adds support for SR-IOV. It causes the driver to spawn up to
+max_vfs worth of virtual function.
+ 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.
+ - The maximum MTU setting for Jumbo Frames is 9216. This value coincides
+ with the maximum Jumbo Frames size of 9234 bytes.
+ - Using Jumbo Frames at 10 or 100 Mbps may result in poor performance or
+ loss of link.
+ The driver utilizes the ethtool interface for driver configuration and
+ diagnostics, as well as displaying statistical information. Ethtool
+ version 3.0 or later is required for this functionality, although we
+ strongly recommend downloading the latest version at:
+ Enabling Wake on LAN* (WoL)
+ WoL is configured through the Ethtool* utility.
+ For instructions on enabling WoL with Ethtool, refer to the Ethtool man page.
+ WoL will be enabled on the system during the next shut down or reboot.
+ For this driver version, in order to enable WoL, the igb driver must be
+ loaded when shutting down or rebooting the system.
+ Wake On LAN is only supported on port A of multi-port adapters.
+ Wake On LAN is not supported for the Intel(R) Gigabit VT Quad Port Server
+ In this mode, a separate MSI-X vector is allocated for each queue and one
+ for "other" interrupts such as link status change and errors. All
+ interrupts are throttled via interrupt moderation. Interrupt moderation
+ must be used to avoid interrupt storms while the driver is processing one
+ interrupt. The moderation value should be at least as large as the expected
+ time for the driver to process an interrupt. Multiqueue is off by default.
+ REQUIREMENTS: MSI-X support is required for Multiqueue. If MSI-X is not
+ found, the system will fallback to MSI or to Legacy interrupts.
+ Large Receive Offload (LRO) is a technique for increasing inbound throughput
+ of high-bandwidth network connections by reducing CPU overhead. It works by
+ aggregating multiple incoming packets from a single stream into a larger
+ buffer before they are passed higher up the networking stack, thus reducing
+ the number of packets that have to be processed. LRO combines multiple
+ Ethernet frames into a single receive in the stack, thereby potentially
+ decreasing CPU utilization for receives.
+ NOTE: LRO requires 2.6.24 or later kernel version. You also need to have
+ inet_lro enabled via either the CONFIG_INET_LRO or CONFIG_INET_LRO_MODULE
+ kernel config option. Additionally, if CONFIG_INET_LRO_MODULE is used, the
+ inet_lro module needs to be loaded before the igb driver.
+ You can verify that the driver is using LRO by looking at these counters in
+ lro_aggregated - count of total packets that were combined
+ lro_flushed - counts the number of packets flushed out of LRO
+ lro_no_desc - counts the number of times an LRO descriptor was not available
+ for the LRO packet
+ NOTE: IPv6 and UDP are not supported by LRO.
+For general information, go to the Intel support website at:
+or the Intel Wired Networking project hosted by Sourceforge at:
+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@xxxxxxxxxxxx
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