docs: networking: device drivers: convert chelsio/cxgb.txt to ReST

.. SPDX-License-Identifier: GPL-2.0

.. include:: <isonum.txt>

=============================================

Chelsio N210 10Gb Ethernet Network Controller

=============================================

Driver Release Notes for Linux

June 20, 2005

CONTENTS

========

.. Contents

 INTRODUCTION

 FEATURES

 PERFORMANCE

 SUPPORT

INTRODUCTION

Introduction

============

 This document describes the Linux driver for Chelsio 10Gb Ethernet Network

 compatible with the Chelsio N110 model 10Gb NICs.

FEATURES

Features

========

Adaptive Interrupts (adaptive-rx)

  ethtool manpage for additional usage information.

  By default, adaptive-rx is disabled.

  To enable adaptive-rx:

  To enable adaptive-rx::

      ethtool -C <interface> adaptive-rx on

  To disable adaptive-rx, use ethtool:

  To disable adaptive-rx, use ethtool::

      ethtool -C <interface> adaptive-rx off

  After disabling adaptive-rx, the timer latency value will be set to 50us.

  You may set the timer latency after disabling adaptive-rx:

  You may set the timer latency after disabling adaptive-rx::

      ethtool -C <interface> rx-usecs <microseconds>

  An example to set the timer latency value to 100us on eth0:

  An example to set the timer latency value to 100us on eth0::

      ethtool -C eth0 rx-usecs 100

  You may also provide a timer latency value while disabling adaptive-rx:

  You may also provide a timer latency value while disabling adaptive-rx::

      ethtool -C <interface> adaptive-rx off rx-usecs <microseconds>

  will be set to the specified value until changed by the user or until

  adaptive-rx is enabled.

  To view the status of the adaptive-rx and timer latency values:

  To view the status of the adaptive-rx and timer latency values::

      ethtool -c <interface>

  Please see the ethtool manpage for additional usage information.

  By default, TSO is enabled.

  To disable TSO:

  To disable TSO::

      ethtool -K <interface> tso off

  To enable TSO:

  To enable TSO::

      ethtool -K <interface> tso on

  To view the status of TSO:

  To view the status of TSO::

      ethtool -k <interface>

PERFORMANCE

Performance

===========

 The following information is provided as an example of how to change system

 your system. You may want to write a script that runs at boot-up which

 includes the optimal settings for your system.

  Setting PCI Latency Timer:

      setpci -d 1425:* 0x0c.l=0x0000F800

  Setting PCI Latency Timer::

      setpci -d 1425::

* 0x0c.l=0x0000F800

  Disabling TCP timestamp::

  Disabling TCP timestamp:

      sysctl -w net.ipv4.tcp_timestamps=0

  Disabling SACK:

  Disabling SACK::

      sysctl -w net.ipv4.tcp_sack=0

  Setting large number of incoming connection requests:

  Setting large number of incoming connection requests::

      sysctl -w net.ipv4.tcp_max_syn_backlog=3000

  Setting maximum receive socket buffer size:

  Setting maximum receive socket buffer size::

      sysctl -w net.core.rmem_max=1024000

  Setting maximum send socket buffer size:

  Setting maximum send socket buffer size::

      sysctl -w net.core.wmem_max=1024000

  Set smp_affinity (on a multiprocessor system) to a single CPU:

  Set smp_affinity (on a multiprocessor system) to a single CPU::

      echo 1 > /proc/irq/<interrupt_number>/smp_affinity

  Setting default receive socket buffer size:

  Setting default receive socket buffer size::

      sysctl -w net.core.rmem_default=524287

  Setting default send socket buffer size:

  Setting default send socket buffer size::

      sysctl -w net.core.wmem_default=524287

  Setting maximum option memory buffers:

  Setting maximum option memory buffers::

      sysctl -w net.core.optmem_max=524287

  Setting maximum backlog (# of unprocessed packets before kernel drops):

  Setting maximum backlog (# of unprocessed packets before kernel drops)::

      sysctl -w net.core.netdev_max_backlog=300000

  Setting TCP read buffers (min/default/max):

  Setting TCP read buffers (min/default/max)::

      sysctl -w net.ipv4.tcp_rmem="10000000 10000000 10000000"

  Setting TCP write buffers (min/pressure/max):

  Setting TCP write buffers (min/pressure/max)::

      sysctl -w net.ipv4.tcp_wmem="10000000 10000000 10000000"

  Setting TCP buffer space (min/pressure/max):

  Setting TCP buffer space (min/pressure/max)::

      sysctl -w net.ipv4.tcp_mem="10000000 10000000 10000000"

  TCP window size for single connections:

   The receive buffer (RX_WINDOW) size must be at least as large as the

   Bandwidth-Delay Product of the communication link between the sender and

   receiver. Due to the variations of RTT, you may want to increase the buffer

   size up to 2 times the Bandwidth-Delay Product. Reference page 289 of

   "TCP/IP Illustrated, Volume 1, The Protocols" by W. Richard Stevens.

   At 10Gb speeds, use the following formula:

   At 10Gb speeds, use the following formula::

       RX_WINDOW >= 1.25MBytes * RTT(in milliseconds)

       Example for RTT with 100us: RX_WINDOW = (1,250,000 * 0.1) = 125,000

   RX_WINDOW sizes of 256KB - 512KB should be sufficient.

   Setting the min, max, and default receive buffer (RX_WINDOW) size:

   Setting the min, max, and default receive buffer (RX_WINDOW) size::

       sysctl -w net.ipv4.tcp_rmem="<min> <default> <max>"

  TCP window size for multiple connections:

   not supported on the machine. Experimentation may be necessary to attain

   the correct value. This method is provided as a starting point for the

   correct receive buffer size.

   Setting the min, max, and default receive buffer (RX_WINDOW) size is

   performed in the same manner as single connection.

DRIVER MESSAGES

Driver Messages

===============

 The following messages are the most common messages logged by syslog. These

 may be found in /var/log/messages.

  Driver up:

  Driver up::

     Chelsio Network Driver - version 2.1.1

  NIC detected:

  NIC detected::

     eth#: Chelsio N210 1x10GBaseX NIC (rev #), PCIX 133MHz/64-bit

  Link up:

  Link up::

     eth#: link is up at 10 Gbps, full duplex

  Link down:

  Link down::

     eth#: link is down

KNOWN ISSUES

Known Issues

============

 These issues have been identified during testing. The following information

      To eliminate the TCP retransmits, set smp_affinity on the particular

      interrupt to a single CPU. You can locate the interrupt (IRQ) used on

      the N110/N210 by using ifconfig:

      the N110/N210 by using ifconfig::

	  ifconfig <dev_name> | grep Interrupt

      Set the smp_affinity to a single CPU:

      Set the smp_affinity to a single CPU::

	  echo 1 > /proc/irq/<interrupt_number>/smp_affinity

      It is highly suggested that you do not run the irqbalance daemon on your

      system, as this will change any smp_affinity setting you have applied.

      The irqbalance daemon runs on a 10 second interval and binds interrupts

      to the least loaded CPU determined by the daemon. To disable this daemon:

      to the least loaded CPU determined by the daemon. To disable this daemon::

	  chkconfig --level 2345 irqbalance off

      By default, some Linux distributions enable the kernel feature,

      irqbalance, which performs the same function as the daemon. To disable

      this feature, add the following line to your bootloader:

      this feature, add the following line to your bootloader::

	  noirqbalance

          Example using the Grub bootloader:

	  Example using the Grub bootloader::

	      title Red Hat Enterprise Linux AS (2.4.21-27.ELsmp)

	      root (hd0,0)

	      kernel /vmlinuz-2.4.21-27.ELsmp ro root=/dev/hda3 noirqbalance

	programming of the PCI-X card, to the following:

	   Data Length (bytes): 1k

	   Total allowed outstanding transactions: 2

      Please refer to AMD 8131-HT/PCI-X Errata 26310 Rev 3.08 August 2004,

      have issues with these settings, please revert to the "safe" settings

      and duplicate the problem before submitting a bug or asking for support.

      NOTE: The default setting on most systems is 8 outstanding transactions

      .. note::

	    The default setting on most systems is 8 outstanding transactions

	    and 2k bytes data length.

  4. On multiprocessor systems, it has been noted that an application which

      particular CPU: runon 0 ifup eth0

SUPPORT

Support

=======

 If you have problems with the software or hardware, please contact our

 customer support team via email at support@chelsio.com or check our website

 at http://www.chelsio.com

===============================================================================

-------------------------------------------------------------------------------

::

 Chelsio Communications

 370 San Aleso Ave.

with this program; if not, write to the Free Software Foundation, Inc.,

59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED

THIS SOFTWARE IS PROVIDED ``AS IS`` AND WITHOUT ANY EXPRESS OR IMPLIED

WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF

MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 Copyright (c) 2003-2005 Chelsio Communications. All rights reserved.

===============================================================================

Copyright |copy| 2003-2005 Chelsio Communications. All rights reserved.

   3com/vortex

   amazon/ena

   aquantia/atlantic

   chelsio/cxgb

.. only::  subproject and html

	  This driver supports Chelsio gigabit and 10-gigabit

	  Ethernet cards. More information about adapter features and

	  performance tuning is in

	  <file:Documentation/networking/device_drivers/chelsio/cxgb.txt>.

	  <file:Documentation/networking/device_drivers/chelsio/cxgb.rst>.

	  For general information about Chelsio and our products, visit

	  our website at <http://www.chelsio.com>.