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authorJeff Kirsher <jeffrey.t.kirsher@intel.com>2010-12-10 02:44:42 -0500
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2010-12-11 01:12:12 -0500
commit072ed34fa97374b390a2493fa281ec8a7888b312 (patch)
tree1baa1cd422c557f7c7ee217a6d4d6b50f05adb36 /Documentation/networking/e1000e.txt
parent96c3c0330dea8856f02fc59e25c866d6d5eebed5 (diff)
Documentation/networking/e1000e.txt: Update documentation
Update Intel Wired LAN e1000e documentation. Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'Documentation/networking/e1000e.txt')
-rw-r--r--Documentation/networking/e1000e.txt40
1 files changed, 22 insertions, 18 deletions
diff --git a/Documentation/networking/e1000e.txt b/Documentation/networking/e1000e.txt
index 6aa048badf32..81a66e69a127 100644
--- a/Documentation/networking/e1000e.txt
+++ b/Documentation/networking/e1000e.txt
@@ -1,5 +1,5 @@
1Linux* Driver for Intel(R) Network Connection 1Linux* Driver for Intel(R) Network Connection
2=============================================================== 2=============================================
3 3
4Intel Gigabit Linux driver. 4Intel Gigabit Linux driver.
5Copyright(c) 1999 - 2010 Intel Corporation. 5Copyright(c) 1999 - 2010 Intel Corporation.
@@ -61,6 +61,12 @@ per second, even if more packets have come in. This reduces interrupt
61load on the system and can lower CPU utilization under heavy load, 61load on the system and can lower CPU utilization under heavy load,
62but will increase latency as packets are not processed as quickly. 62but will increase latency as packets are not processed as quickly.
63 63
64The default behaviour of the driver previously assumed a static
65InterruptThrottleRate value of 8000, providing a good fallback value for
66all traffic types, but lacking in small packet performance and latency.
67The hardware can handle many more small packets per second however, and
68for this reason an adaptive interrupt moderation algorithm was implemented.
69
64The driver has two adaptive modes (setting 1 or 3) in which 70The driver has two adaptive modes (setting 1 or 3) in which
65it dynamically adjusts the InterruptThrottleRate value based on the traffic 71it dynamically adjusts the InterruptThrottleRate value based on the traffic
66that it receives. After determining the type of incoming traffic in the last 72that 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
86the same as mode 3, the InterruptThrottleRate will be increased stepwise to 92the same as mode 3, the InterruptThrottleRate will be increased stepwise to
8770000 for traffic in class "Lowest latency". 9370000 for traffic in class "Lowest latency".
88 94
89In simplified mode the interrupt rate is based on the ratio of Tx and 95In simplified mode the interrupt rate is based on the ratio of TX and
90Rx traffic. If the bytes per second rate is approximately equal the 96RX traffic. If the bytes per second rate is approximately equal, the
91interrupt rate will drop as low as 2000 interrupts per second. If the 97interrupt rate will drop as low as 2000 interrupts per second. If the
92traffic is mostly transmit or mostly receive, the interrupt rate could 98traffic is mostly transmit or mostly receive, the interrupt rate could
93be as high as 8000. 99be as high as 8000.
@@ -177,7 +183,7 @@ Copybreak
177Valid Range: 0-xxxxxxx (0=off) 183Valid Range: 0-xxxxxxx (0=off)
178Default Value: 256 184Default Value: 256
179 185
180Driver copies all packets below or equaling this size to a fresh Rx 186Driver copies all packets below or equaling this size to a fresh RX
181buffer before handing it up the stack. 187buffer before handing it up the stack.
182 188
183This parameter is different than other parameters, in that it is a 189This parameter is different than other parameters, in that it is a
@@ -223,17 +229,17 @@ loading or enabling the driver, try disabling this feature.
223 229
224WriteProtectNVM 230WriteProtectNVM
225--------------- 231---------------
226Valid Range: 0-1 232Valid Range: 0,1
227Default Value: 1 (enabled) 233Default Value: 1
228 234
229Set the hardware to ignore all write/erase cycles to the GbE region in the 235If set to 1, configure the hardware to ignore all write/erase cycles to the
230ICHx NVM (non-volatile memory). This feature can be disabled by the 236GbE region in the ICHx NVM (in order to prevent accidental corruption of the
231WriteProtectNVM module parameter (enabled by default) only after a hardware 237NVM). This feature can be disabled by setting the parameter to 0 during initial
232reset, but the machine must be power cycled before trying to enable writes. 238driver load.
233 239NOTE: The machine must be power cycled (full off/on) when enabling NVM writes
234Note: the kernel boot option iomem=relaxed may need to be set if the kernel 240via setting the parameter to zero. Once the NVM has been locked (via the
235config option CONFIG_STRICT_DEVMEM=y, if the root user wants to write the 241parameter at 1 when the driver loads) it cannot be unlocked except via power
236NVM from user space via ethtool. 242cycle.
237 243
238Additional Configurations 244Additional Configurations
239========================= 245=========================
@@ -259,7 +265,6 @@ Additional Configurations
259 - Some adapters limit Jumbo Frames sized packets to a maximum of 265 - Some adapters limit Jumbo Frames sized packets to a maximum of
260 4096 bytes and some adapters do not support Jumbo Frames. 266 4096 bytes and some adapters do not support Jumbo Frames.
261 267
262
263 Ethtool 268 Ethtool
264 ------- 269 -------
265 The driver utilizes the ethtool interface for driver configuration and 270 The driver utilizes the ethtool interface for driver configuration and
@@ -283,8 +288,7 @@ Additional Configurations
283 loaded when shutting down or rebooting the system. 288 loaded when shutting down or rebooting the system.
284 289
285 In most cases Wake On LAN is only supported on port A for multiple port 290 In most cases Wake On LAN is only supported on port A for multiple port
286 adapters. To verify if a port supports Wake on LAN run ethtool eth<X>. 291 adapters. To verify if a port supports Wake on Lan run Ethtool eth<X>.
287
288 292
289Support 293Support
290======= 294=======