readme.txt

网络编程,关于网卡驱动方面的资料.

    1      full duplex (default)
    
    
rx_flow_control

    Enables or disables receiving flow control (pause) frames. This parameter
    is used together with auto_flow_control. The valid values are:
    
    0      pause receive disabled
    1      pause receive enabled if auto_flow_control is set to 0, or
           pause receive advertised if auto_flow_control is set to 1 (default)

tx_flow_control

    Enables or disables transmitting flow control (pause) frames. This parameter
    is used together with auto_flow_control. The valid values are:
    
    0      pause transmit disabled
    1      pause transmit enabled if auto_flow_control is set to 0, or
           pause transmit advertised if auto_flow_control is set to 1 (default)

auto_flow_control

    Enables or disables autonegotiation of flow control. This parameter is used
    together with rx_flow_control and tx_flow_control to determine the
    advertised flow control capability. The valid values are:
    
    0      flow control autonegotiation disabled
    1      flow control autonegotiation enabled with capability specified in
           rx_flow_control and tx_flow_control (only valid if line_speed is
           set to 0 or auto_speed is set to 1) (default)

mtu

    Enables jumbo frames up to the specified MTU size. The valid range for
    this parameter is 1500 to 9000. Default is 1500 which is standard
    ethernet (non-jumbo) MTU size. Note that the MTU size excludes the
    ethernet header size of 14 bytes. Actual frame size is MTU size + 14 bytes.
    Jumbo MTU sizes are not supported on BCM5705 chips.

    The MTU size can also be changed using ifconfig after the driver is loaded.
    See the ifconfig man page for details.

tx_checksum

    Enables or disables hardware transmit TCP/UDP checksum. The valid values
    are:

    0      checksum disabled
    1      checksum enabled (default)

rx_checksum

    Enables or disables hardware receive TCP/UDP checksum validation. The
    valid values are:

    0      checksum disabled
    1      checksum enabled (default)

scatter_gather

    Enables or disables scatter-gather and 64-bit DMA on x86. This option is
    only useful when running on TUX-enabled kernels or newer kernels with
    zero-copy TCP. The valid values are:

    0      scatter-gather and 64-bit DMA on x86 disabled
    1      scatter-gather and 64-bit DMA on x86 enabled (default)

nic_tx_bd

    Enables either NIC based or host based transmit buffer descriptors (Tx BDs).
    NIC based Tx BDs may be slightly faster on certain machines on earlier
    2.4 kernels where each transmit packet is usually entirely contiguous. On
    later kernels with scatter-gather and TCP segmentation option, host based
    Tx BDs using DMA transfer are usually faster. NIC based Tx BDs are not
    supported on 5705 family controllers. The valid values are:

    0      NIC based transmit buffer descriptors disabled (using host based
           transmit buffer descriptors) (default)
    1      NIC based transmit buffer descriptors enabled (not supported
           on 5705 family controllers)

tx_pkt_desc_cnt

    Configures the number of transmit descriptors. Default is 120. The
    valid range is from 1 to 511. Note that the driver may not be able to
    allocate the required amount of memory if this parameter is set too high.
    Depending on kernel and CPU architecture, each descriptor may require up
    to about 268 bytes. This parameter should not be set less than 80 if
    adaptive_coalesce (see below) is enabled.

rx_std_desc_cnt

    Configures the number of receive descriptors for frames up to 1528 bytes.
    Default is 200. The valid range is from 1 to 511. This parameter should
    not be set less than 80 on systems with high network traffic. Setting this
    parameter higher allows the NIC to buffer larger bursts of network
    traffic without dropping frames, especially on slower systems. Note that
    the driver may not be able to allocate the required amount of memory if
    this parameter is set too high. Depending on kernel and CPU architecture,
    each descriptor may require up to about 268 bytes. Each descriptor also
    requires a socket buffer of at least 1536 bytes. This parameter should not
    be set less than 50 if adaptive_coalesce (see below) is enabled.

rx_jumbo_desc_cnt

    Configures the number of receive descriptors for jumbo frames larger
    than 1528 bytes. Default is 128 and valid range is from 1 to 255.
    When jumbo frames larger than 1528 bytes are used, this parameter should
    not be set lower than 60 on systems with high network traffic. Setting
    this parameter higher allows the NIC to buffer larger bursts of jumbo
    traffic without dropping frames, especially on slower systems. Depending
    on kernel and CPU architecture, each descriptor may require up to about
    268 bytes. Each descriptor also requires a socket buffer the size of a
    maximum jumbo frame. On systems with insufficient memory, it may be
    necessary to reduce this parameter. This parameter should not be set less
    than 50 if adaptive_coalesce (see below) is enabled. When the maximum
    frame size is 1528 or smaller (MTU size 1514 or smaller), this parameter
    is not used and is always 0.

adaptive_coalesce

    Enables or disables adaptive adjustments to the various interrupt
    coalescing parameters. Enabling it allows the driver to dynamically
    adjust the interrupt coalescing parameters to achieve high throughput
    during heavy traffic and low latency during light traffic.
    rx_std_desc_cnt, (and rx_jumbo_desc_cnt if using jumbo frames) should not
    be set less than 50, and tx_pkt_desc_cnt should not be set less than 80
    when this parameter is enabled. Note that if the kernel supports the NAPI
    receive polling mode, interrupt coalescing will be handled in a different
    way and this parameter will not be used. The valid values are:

    0      disabled (always disabled in NAPI mode)
    1      enabled (default)

rx_coalesce_ticks

    Configures the number of 1 usec ticks before the NIC generates receive
    interrupt after receiving a frame. This parameter works in conjunction
    with the rx_max_coalesce_frames parameter. Interrupt will be generated
    when either of these thresholds is exceeded. 0 means this parameter is
    ignored and interrupt will be generated when the rx_max_coalesce_frames
    threshold is reached. The valid range is from 0 to 500, and default is
    60 (18 if using NAPI mode). This parameter is not used and will be
    adjusted automatically if adaptive_coalesce is set to 1.

rx_max_coalesce_frames

    Configures the number of received frames before the NIC generates receive
    interrupt. The valid range is from 0 to 100, and default is 15 (6 if using
    NAPI mode). This parameter and rx_coalesce_ticks cannot be both 0,
    otherwise no receive interrupts will be generated. It should also be set
    lower than rx_std_desc_cnt (and rx_jumbo_desc_cnt if using jumbo frames).
    This parameter is not used and will be adjusted automatically if
    adaptive_coalesce is set to 1.

tx_coalesce_ticks

    Configures the number of 1 usec ticks before the NIC generates transmit
    interrupt after transmitting a frame. This parameter works in conjunction
    with the tx_max_coalesce_frames parameter. Interrupt will be generated
    when either of these thresholds is exceeded. 0 means this
    parameter is ignored and interrupt will be generated when the
    tx_max_coalesce_frames threshold is reached. The valid range is from 0 to
    500, and default is 200. This parameter is not used and will be adjusted
    automatically if adaptive_coalesce is set to 1.

tx_max_coalesce_frames

    Configures the number of transmitted frames before the NIC generates
    transmit interrupt. The valid range is from 0 to 100, and default is 35.
    This parameter and tx_coalesce_ticks cannot be both 0, otherwise no
    transmit completion interrupt will be generated. This parameter should
    always be set lower than tx_pkt_desc_cnt. This parameter is not used and
    will be adjusted automatically if adaptive_coalesce is set to 1.

stats_coalesce_ticks

    Configures the number of 1 usec ticks between periodic statistics updates 
    (DMAs). The valid range is from 100 to 3600000000, and default is 1000000
    (1 sec.). 0 is also valid and is used to disable statistics updates.
    This parameter is not used and will be set to default if adaptive_coalesce
    is set to 1. Please note that the valid range may vary by kernel version.

enable_wol

    Enables or disables magic packet Wake-On-LAN when the system is shutdown.
    Note that not all systems support Wake-On-LAN. The valid values are:

    0    magic packet Wake-On-LAN disabled (default)
    1    magic packet Wake-On-LAN enabled

enable_tso

    Enables or disables TCP Segmentation Option (TSO) when using kernels that
    support it. This parameter is only defined on newer kernels that support
    TSO. The valid values are:

    0    TSO disabled
    1    TSO enabled (default)

vlan_tag_mode

    This parameter controls the stripping of VLAN tags on incoming packets,
    and is used to allow VLAN tagged ASF or IPMI packets to be received
    properly. The valid values are:

    0    Auto mode (default)
    1    Normal strip mode
    2    Forced strip mode

    In normal mode, VLAN tags are only stripped if VLANs are registered
    by the 802.1q VLAN module or BASP. In forced strip mode, VLAN tags
    are always stripped. Auto mode will select normal strip mode if ASF/IPMI
    is disabled, or forced strip mode if ASF/IPMI is enabled.

delay_link

    If set to 1, this parameter will cause the driver to return 
    -EOPNOTSUPP when the SIOCGMIIREG or ETHTOOL_GLINK ioctls are called
    during the first 6 seconds after driver reset. When the driver resets
    the NIC during ifconfig, the link will drop and it may take several
    seconds for the link to come up after autonegotiation completes. Some
    applications, such as ifup, may not wait long enough for the link
    before giving up. Setting this parameter to 1 may get around such
    problems. The default value is 0, which means that the driver will
    always return true link states to all ioctl calls, when applicable.

disable_d3hot

    If set to 1, this parameter will cause the driver to never
    put the device in D3Hot power state when the NIC is shutdown or
    suspended. If set, this parameter will also disable the Wake-On-Lan
    setting. A rare D3Hot related problem was seen during repeated
    shutdown of PCI Express devices on systems running 2.6 kernels.

Driver Messages
===============

The following are the most common sample messages that may be logged in the file
/var/log/messages. Use dmesg -n <level> to control the level at which messages
will appear on the console. Most systems are set to level 6 by default.

Broadcom Gigabit Ethernet Driver bcm5700 with Broadcom NIC Extension (NICE)
ver. 7.4.11 (12/15/04)

    Driver signon


eth#: Broadcom BCM5704 1000Base-T found at mem faff0000, IRQ 16, node addr
0010180402d8
eth#: Broadcom BCM5704 Integrated Copper transceiver found
eth#: Scatter-gather ON, 64-bit DMA ON, Tx Checksum ON, Rx Checksum ON, 802.1Q VLAN ON, TSO ON, NAPI ON

    NIC detected


bcm5700: eth# NIC Link is Up, 1000 Mbps full duplex, receive and transmit flow control ON

    Link up and speed indication


bcm5700: eth# NIC Link is Down

    Link down indication


Statistics
==========

Detailed statistics and configuration information can be viewed in the file
/proc/net/nicinfo/eth#.info.