Commit 072ed34f authored by Jeff Kirsher's avatar Jeff Kirsher

Documentation/networking/e1000e.txt: Update documentation

Update Intel Wired LAN e1000e documentation.
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent 96c3c033
Linux* Driver for Intel(R) Network Connection
===============================================================
=============================================
Intel Gigabit Linux driver.
Copyright(c) 1999 - 2010 Intel Corporation.
......@@ -61,6 +61,12 @@ 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.
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
......@@ -86,8 +92,8 @@ 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".
In simplified mode the interrupt rate is based on the ratio of Tx and
Rx traffic. If the bytes per second rate is approximately equal the
In simplified mode the interrupt rate is based on the ratio of TX and
RX traffic. If the bytes per second rate is approximately equal, the
interrupt rate will drop as low as 2000 interrupts per second. If the
traffic is mostly transmit or mostly receive, the interrupt rate could
be as high as 8000.
......@@ -177,7 +183,7 @@ Copybreak
Valid Range: 0-xxxxxxx (0=off)
Default Value: 256
Driver copies all packets below or equaling this size to a fresh Rx
Driver copies all packets below or equaling this size to a fresh RX
buffer before handing it up the stack.
This parameter is different than other parameters, in that it is a
......@@ -223,17 +229,17 @@ loading or enabling the driver, try disabling this feature.
WriteProtectNVM
---------------
Valid Range: 0-1
Default Value: 1 (enabled)
Set the hardware to ignore all write/erase cycles to the GbE region in the
ICHx NVM (non-volatile memory). This feature can be disabled by the
WriteProtectNVM module parameter (enabled by default) only after a hardware
reset, but the machine must be power cycled before trying to enable writes.
Note: the kernel boot option iomem=relaxed may need to be set if the kernel
config option CONFIG_STRICT_DEVMEM=y, if the root user wants to write the
NVM from user space via ethtool.
Valid Range: 0,1
Default Value: 1
If set to 1, configure the hardware to ignore all write/erase cycles to the
GbE region in the ICHx NVM (in order to prevent accidental corruption of the
NVM). This feature can be disabled by setting the parameter to 0 during initial
driver load.
NOTE: The machine must be power cycled (full off/on) when enabling NVM writes
via setting the parameter to zero. Once the NVM has been locked (via the
parameter at 1 when the driver loads) it cannot be unlocked except via power
cycle.
Additional Configurations
=========================
......@@ -259,7 +265,6 @@ Additional Configurations
- Some adapters limit Jumbo Frames sized packets to a maximum of
4096 bytes and some adapters do not support Jumbo Frames.
Ethtool
-------
The driver utilizes the ethtool interface for driver configuration and
......@@ -283,8 +288,7 @@ Additional Configurations
loaded when shutting down or rebooting the system.
In most cases Wake On LAN is only supported on port A for multiple port
adapters. To verify if a port supports Wake on LAN run ethtool eth<X>.
adapters. To verify if a port supports Wake on Lan run Ethtool eth<X>.
Support
=======
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment