Ubuntu Manpage: sk98lin - Marvell/SysKonnect Gigabit Ethernet driver v6.21

NAME

       sk98lin - Marvell/SysKonnect Gigabit Ethernet driver v6.21

SYNOPSIS

       insmod   sk98lin.o   [Speed_A=i,j,...]    [Speed_B=i,j,...]    [AutoNeg_A=i,j,...]    [AutoNeg_B=i,j,...]
       [DupCap_A=i,j,...]   [DupCap_B=i,j,...]   [FlowCtrl_A=i,j,...]   [FlowCtrl_B=i,j,...]    [Role_A=i,j,...]
       [Role_B=i,j,...]    [ConType=i,j,...]    [Moderation=i,j,...]   [IntsPerSec=i,j,...]   [PrefPort=i,j,...]
       [RlmtMode=i,j,...]

DESCRIPTION

Note: This obsolete driver was removed from the kernel in version 2.6.26.

sk98lin is the Gigabit Ethernet driver for Marvell and SysKonnect network adapter cards. It supports
SysKonnect SK-98xx/SK-95xx compliant Gigabit Ethernet Adapter and any Yukon compliant chipset.

When loading the driver using insmod, parameters for the network adapter cards might be stated as a
sequence of comma separated commands. If for instance two network adapters are installed and
AutoNegotiation on Port A of the first adapter should be ON, but on the Port A of the second adapter
switched OFF, one must enter:

insmod sk98lin.o AutoNeg_A=On,Off

After sk98lin is bound to one or more adapter cards and the /proc filesystem is mounted on your system, a
dedicated statistics file will be created in the folder /proc/net/sk98lin for all ports of the installed
network adapter cards. Those files are named eth[x] whereas x is the number of the interface that has
been assigned to a dedicated port by the system.

If loading is finished, any desired IP address can be assigned to the respective eth[x] interface using
the ifconfig(8) command. This causes the adapter to connect to the Ethernet and to display a status
message on the console saying "ethx: network connection up using port y" followed by the configured or
detected connection parameters.

The sk98lin also supports large frames (also called jumbo frames). Using jumbo frames can improve
throughput tremendously when transferring large amounts of data. To enable large frames, the MTU
(maximum transfer unit) size for an interface is to be set to a high value. The default MTU size is 1500
and can be changed up to 9000 (bytes). Setting the MTU size can be done when assigning the IP address to
the interface or later by using the ifconfig(8) command with the mtu parameter. If for instance eth0
needs an IP address and a large frame MTU size, the following two commands might be used:

ifconfig eth0 10.1.1.1
ifconfig eth0 mtu 9000

Those two commands might even be combined into one:

ifconfig eth0 10.1.1.1 mtu 9000

Note that large frames can be used only if permitted by your network infrastructure. This means, that
any switch being used in your Ethernet must also support large frames. Quite some switches support large
frames, but need to be configured to do so. Most of the times, their default setting is to support only
standard frames with an MTU size of 1500 (bytes). In addition to the switches inside the network, all
network adapters that are to be used must also be enabled regarding jumbo frames. If an adapter is not
set to receive large frames it will simply drop them.

Switching back to the standard Ethernet frame size can be done by using the ifconfig(8) command again:

ifconfig eth0 mtu 1500

The Marvell/SysKonnect Gigabit Ethernet driver for Linux is able to support VLAN and Link Aggregation
according to IEEE standards 802.1, 802.1q, and 802.3ad. Those features are available only after
installation of open source modules which can be found on the Internet:

VLAN: http://www.candelatech.com/~greear/vlan.html
Link Aggregation: http://www.st.rim.or.jp/~yumo

Note that Marvell/SysKonnect does not offer any support for these open source modules and does not take
the responsibility for any kind of failures or problems arising when using these modules.

Parameters
Speed_A=i,j,...
This parameter is used to set the speed capabilities of port A of an adapter card. It is valid
only for Yukon copper adapters. Possible values are: 10, 100, 1000 or Auto whereas Auto is the
default. Usually, the speed is negotiated between the two ports during link establishment. If
this fails, a port can be forced to a specific setting with this parameter.

Speed_B=i,j,...
This parameter is used to set the speed capabilities of port B of an adapter card. It is valid
only for Yukon copper adapters. Possible values are: 10, 100, 1000 or Auto whereas Auto is the
default. Usually, the speed is negotiated between the two ports during link establishment. If
this fails, a port can be forced to a specific setting with this parameter.

AutoNeg_A=i,j,...
Enables or disables the use of autonegotiation of port A of an adapter card. Possible values are:
On, Off or Sense whereas On is the default. The Sense mode automatically detects whether the link
partner supports auto-negotiation or not.

AutoNeg_B=i,j,...
Enables or disables the use of autonegotiation of port B of an adapter card. Possible values are:
On, Off or Sense whereas On is the default. The Sense mode automatically detects whether the link
partner supports auto-negotiation or not.

DupCap_A=i,j,...
This parameter indicates the duplex mode to be used for port A of an adapter card. Possible
values are: Half, Full or Both whereas Both is the default. This parameter is relevant only if
AutoNeg_A of port A is not set to Sense. If AutoNeg_A is set to On, all three values of DupCap_A
( Half, Full or Both) might be stated. If AutoNeg_A is set to Off, only DupCap_A values Full and
Half are allowed. This DupCap_A parameter is useful if your link partner does not support all
possible duplex combinations.

DupCap_B=i,j,...
This parameter indicates the duplex mode to be used for port B of an adapter card. Possible
values are: Half, Full or Both whereas Both is the default. This parameter is relevant only if
AutoNeg_B of port B is not set to Sense. If AutoNeg_B is set to On, all three values of DupCap_B
( Half, Full or Both) might be stated. If AutoNeg_B is set to Off, only DupCap_B values Full and
Half are allowed. This DupCap_B parameter is useful if your link partner does not support all
possible duplex combinations.

FlowCtrl_A=i,j,...
This parameter can be used to set the flow control capabilities the port reports during auto-
negotiation. Possible values are: Sym, SymOrRem, LocSend or None whereas SymOrRem is the default.
The different modes have the following meaning:

Sym = Symmetric
both link partners are allowed to send PAUSE frames
SymOrRem = SymmetricOrRemote
both or only remote partner are allowed to send PAUSE frames
LocSend = LocalSend
only local link partner is allowed to send PAUSE frames
None = None
no link partner is allowed to send PAUSE frames

Note that this parameter is ignored if AutoNeg_A is set to Off.

FlowCtrl_B=i,j,...
This parameter can be used to set the flow control capabilities the port reports during auto-
negotiation. Possible values are: Sym, SymOrRem, LocSend or None whereas SymOrRem is the default.
The different modes have the following meaning:

Note that this parameter is ignored if AutoNeg_B is set to Off.

Role_A=i,j,...
This parameter is valid only for 1000Base-T adapter cards. For two 1000Base-T ports to
communicate, one must take the role of the master (providing timing information), while the other
must be the slave. Possible values are: Auto, Master or Slave whereas Auto is the default.
Usually, the role of a port is negotiated between two ports during link establishment, but if that
fails the port A of an adapter card can be forced to a specific setting with this parameter.

Role_B=i,j,...
This parameter is valid only for 1000Base-T adapter cards. For two 1000Base-T ports to
communicate, one must take the role of the master (providing timing information), while the other
must be the slave. Possible values are: Auto, Master or Slave whereas Auto is the default.
Usually, the role of a port is negotiated between two ports during link establishment, but if that
fails the port B of an adapter card can be forced to a specific setting with this parameter.

ConType=i,j,...
This parameter is a combination of all five per-port parameters within one single parameter. This
simplifies the configuration of both ports of an adapter card. The different values of this
variable reflect the most meaningful combinations of port parameters. Possible values and their
corresponding combination of per-port parameters:

Stating any other port parameter together with this ConType parameter will result in a merged
configuration of those settings. This is due to the fact, that the per-port parameters (e.g.,
Speed_A) have a higher priority than the combined variable ConType.

Moderation=i,j,...
Interrupt moderation is employed to limit the maximum number of interrupts the driver has to
serve. That is, one or more interrupts (which indicate any transmit or receive packet to be
processed) are queued until the driver processes them. When queued interrupts are to be served,
is determined by the IntsPerSec parameter, which is explained later below. Possible moderation
modes are: None, Static or Dynamic whereas None is the default. The different modes have the
following meaning:

None No interrupt moderation is applied on the adapter card. Therefore, each transmit or receive
interrupt is served immediately as soon as it appears on the interrupt line of the adapter card.

Static Interrupt moderation is applied on the adapter card. All transmit and receive interrupts
are queued until a complete moderation interval ends. If such a moderation interval ends, all
queued interrupts are processed in one big bunch without any delay. The term Static reflects the
fact, that interrupt moderation is always enabled, regardless how much network load is currently
passing via a particular interface. In addition, the duration of the moderation interval has a
fixed length that never changes while the driver is operational.

Dynamic Interrupt moderation might be applied on the adapter card, depending on the load of the
system. If the driver detects that the system load is too high, the driver tries to shield the
system against too much network load by enabling interrupt moderation. If—at a later time—the CPU
utilization decreases again (or if the network load is negligible) the interrupt moderation will
automatically be disabled.

Interrupt moderation should be used when the driver has to handle one or more interfaces with a
high network load, which—as a consequence—leads also to a high CPU utilization. When moderation
is applied in such high network load situations, CPU load might be reduced by 20-30% on slow
computers.

Note that the drawback of using interrupt moderation is an increase of the round-trip-time (RTT),
due to the queuing and serving of interrupts at dedicated moderation times.

IntsPerSec=i,j,...
This parameter determines the length of any interrupt moderation interval. Assuming that static
interrupt moderation is to be used, an IntsPerSec parameter value of 2000 will lead to an
interrupt moderation interval of 500 microseconds. Possible values for this parameter are in the
range of 30...40000 (interrupts per second). The default value is 2000.

This parameter is used only if either static or dynamic interrupt moderation is enabled on a
network adapter card. This parameter is ignored if no moderation is applied.

Note that the duration of the moderation interval is to be chosen with care. At first glance,
selecting a very long duration (e.g., only 100 interrupts per second) seems to be meaningful, but
the increase of packet-processing delay is tremendous. On the other hand, selecting a very short
moderation time might compensate the use of any moderation being applied.

PrefPort=i,j,...
This parameter is used to force the preferred port to A or B (on dual-port network adapters). The
preferred port is the one that is used if both ports A and B are detected as fully functional.
Possible values are: A or B whereas A is the default.

RlmtMode=i,j,...
RLMT monitors the status of the port. If the link of the active port fails, RLMT switches
immediately to the standby link. The virtual link is maintained as long as at least one
"physical" link is up. This parameters states how RLMT should monitor both ports. Possible
values are: CheckLinkState, CheckLocalPort, CheckSeg or DualNet whereas CheckLinkState is the
default. The different modes have the following meaning:

CheckLinkState Check link state only: RLMT uses the link state reported by the adapter hardware
for each individual port to determine whether a port can be used for all network traffic or not.

CheckLocalPort In this mode, RLMT monitors the network path between the two ports of an adapter by
regularly exchanging packets between them. This mode requires a network configuration in which
the two ports are able to "see" each other (i.e., there must not be any router between the ports).

CheckSeg Check local port and segmentation: This mode supports the same functions as the
CheckLocalPort mode and additionally checks network segmentation between the ports. Therefore,
this mode is to be used only if Gigabit Ethernet switches are installed on the network that have
been configured to use the Spanning Tree protocol.

DualNet In this mode, ports A and B are used as separate devices. If you have a dual port
adapter, port A will be configured as eth[x] and port B as eth[x+1]. Both ports can be used
independently with distinct IP addresses. The preferred port setting is not used. RLMT is turned
off.

Note that RLMT modes CheckLocalPort and CheckLinkState are designed to operate in configurations
where a network path between the ports on one adapter exists. Moreover, they are not designed to
work where adapters are connected back-to-back.

FILES

       /proc/net/sk98lin/eth[x]
              The statistics file of a particular interface of an adapter card.  It contains generic information
              about the adapter card plus a detailed summary of all transmit and receive counters.

       /usr/src/linux/Documentation/networking/sk98lin.txt
              This  is  the  README  file  of the sk98lin driver.  It contains a detailed installation HOWTO and
              describes all parameters of the driver.  It denotes also common problems and provides the solution
              to them.

BUGS

       Report any bugs to linux@syskonnect.de

COLOPHON