NAME | SYNOPSIS | DESCRIPTION | FILES | BUGS | SEE ALSO | COLOPHON
SK98LIN(4) Linux Programmer's Manual SK98LIN(4)
sk98lin - Marvell/SysKonnect Gigabit Ethernet driver v6.21
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,...] [FlowC-
trl_A=i,j,...] [FlowCtrl_B=i,j,...] [Role_A=i,j,...] [Role_B=i,j,...]
[ConType=i,j,...] [Moderation=i,j,...] [IntsPerSec=i,j,...] [Pref-
Port=i,j,...] [RlmtMode=i,j,...]
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 file system
is mounted on your system, a dedicated statistics file will be created in
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 only be used 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 only available 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.
Speed_A=i,j,...
This parameter is used to set the speed capabilities of port A of an
adapter card. It is only valid 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 only valid 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 only relevant 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 only relevant 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:
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_B is set to Off.
Role_A=i,j,...
This parameter is only valid 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 only valid 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:
ConType | DupCap AutoNeg FlowCtrl Role Speed
--------+-------------------------------------------
Auto | Both On SymOrRem Auto Auto
100FD | Full Off None Auto 100
100HD | Half Off None Auto 100
10FD | Full Off None Auto 10
10HD | Half Off None Auto 10
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 only used, 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 only to be
used 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.
/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.
Report any bugs to linux@syskonnect.de
ifconfig(8), insmod(8), modprobe(8)
This page is part of release 3.23 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
Linux 2007-11-25 SK98LIN(4)