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,...
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,...
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 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 your network infrastructure allows to do so. 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]
andport
Bas
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/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 solution to them.
modprobe(8), insmod(8), ifconfig(8)
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