sk98lin
SK98LIN(4) SK98LIN(4)
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,...] [Dup-
Cap_B=i,j,...] [FlowCtrl_A=i,j,...] [FlowCtrl_B=i,j,...]
[Role_A=i,j,...] [Role_B=i,j,...] [ConType=i,j,...] [Modera-
tion=i,j,...] [IntsPerSec=i,j,...] [PrefPort=i,j,...] [Rlmt-
Mode=i,j,...]
DESCRIPTION
sk98lin is the Gigabit Ethernet driver for Marvell and SysKonnect net-
work 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 com-
mands. If for instance two network adapters are installed and AutoNe-
gotiation 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 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" fol-
lowed 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 transfer-
ring 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). Set-
ting 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 your network infrastructure
allows to do so. This means, that any switch being used in your Ether-
net 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 net-
work 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 installa-
tion 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 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 set-
tings. This is due to the fact, that the per-port parameters
(e.g. Speed_A ) have a higher priority than the combined vari-
able 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 inter-
rupts (which indicate any transmit or receive packet to be pro-
cessed) 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 immedi-
ately 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 utiliza-
tion 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 han-
dle one or more interfaces with a high network load, which - as
a consequence - leads also to a high CPU utilization. When mod-
eration 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 modera-
tion 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 cho-
sen 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 func-
tional. 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 , CheckLocal-
Port , 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 configura-
tion 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 con-
figured as eth[x]andportBas eth[x+1]
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/network/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 solu-
tion to them.
BUGS
Report any bugs to linux@syskonnect.de
AUTHORS
Ralph Roesler - rroesler@syskonnect.de
Mirko Lindner - mlindner@syskonnect.de
SEE ALSO
modprobe(8), insmod(8), ifconfig(8).
sk98lin 6.21 2003/12/17 10:03:18 SK98LIN(4)
