dc
—
DEC/Intel 21143 and clone 10/100 Ethernet driver
To compile this driver into the kernel, place the following lines in your kernel
configuration file:
device miibus
device dc
Alternatively, to load the driver as a module at boot time, place
the following line in
loader.conf(5):
The dc
driver provides support for several PCI Fast
Ethernet adapters and embedded controllers based on the DEC/Intel 21143
chipset and clones.
All of supported chipsets have the same general register layout,
DMA descriptor format and method of operation. All of the clone chips are
based on the 21143 design with various modifications. The 21143 itself has
support for 10baseT, BNC, AUI, MII and symbol media attachments, 10 and
100Mbps speeds in full or half duplex, built in NWAY autonegotiation and
wake on LAN. The 21143 also offers several receive filter programming
options including perfect filtering, inverse perfect filtering and hash
table filtering.
Some clone chips duplicate the 21143 fairly closely while others
only maintain superficial similarities. Some support only MII media
attachments. Others use different receiver filter programming mechanisms. At
least one supports only chained DMA descriptors (most support both chained
descriptors and contiguously allocated fixed size rings). Some chips
(especially the PNIC) also have peculiar bugs. The
dc
driver does its best to provide generalized
support for all of these chipsets in order to keep special case code to a
minimum.
These chips are used by many vendors which makes it difficult to
provide a complete list of all supported cards.
The dc
driver supports the following media
types:
autoselect
- Enable autoselection of the media type and options. The user can manually
override the autoselected mode by adding media options to the
/etc/rc.conf file.
Note: the built-in NWAY autonegotiation on the original PNIC
82c168 chip is horribly broken and is not supported by the
dc
driver at this time (see the
BUGS section for details). The original
82c168 appears on very early revisions of the LinkSys LNE100TX and
Matrox FastNIC.
10baseT/UTP
- Set 10Mbps operation. The
mediaopt
option can also
be used to enable full-duplex
operation. Not
specifying full-duplex
implies
half-duplex
mode.
100baseTX
- Set 100Mbps (Fast Ethernet) operation. The
mediaopt
option can also be used to enable
full-duplex
operation. Not specifying
full-duplex
implies
half-duplex
mode.
The dc
driver supports the following media
options:
full-duplex
- Force full duplex operation. The interface will operate in half duplex
mode if this media option is not specified.
Note that the 100baseTX media type may not be available on certain
Intel 21143 adapters which support 10Mbps media attachments only. For more
information on configuring this device, see
ifconfig(8).
The dc
driver provides support for the following
chipsets:
- DEC/Intel 21143
- ADMtek AL981 Comet, AN985 Centaur, ADM9511 Centaur II and ADM9513 Centaur
II
- ALi/ULi M5261 and M5263
- ASIX Electronics AX88140A and AX88141
- Conexant LANfinity RS7112 (miniPCI)
- Davicom DM9009, DM9100, DM9102 and DM9102A
- Lite-On 82c168 and 82c169 PNIC
- Lite-On/Macronix 82c115 PNIC II
- Macronix 98713, 98713A, 98715, 98715A, 98715AEC-C, 98725, 98727 and
98732
- Xircom X3201 (cardbus only)
The following NICs are known to work with the
dc
driver at this time:
- 3Com OfficeConnect 10/100B (ADMtek AN985 Centaur-P)
- Abocom FE2500
- Accton EN1217 (98715A)
- Accton EN2242 MiniPCI
- Adico AE310TX (98715A)
- Alfa Inc GFC2204 (ASIX AX88140A)
- Built in 10Mbps only Ethernet on Compaq Presario 7900 series desktops
(21143, non-MII)
- Built in Ethernet on LinkSys EtherFast 10/100 Instant GigaDrive (DM9102,
MII)
- CNet Pro110B (ASIX AX88140A)
- CNet Pro120A (98715A or 98713A) and CNet Pro120B (98715)
- Compex RL100-TX (98713 or 98713A)
- D-Link DFE-570TX (21143, MII, quad port)
- Digital DE500-BA 10/100 (21143, non-MII)
- ELECOM Laneed LD-CBL/TXA (ADMtek AN985)
- Hawking CB102 CardBus
- IBM EtherJet Cardbus Adapter
- Intel PRO/100 Mobile Cardbus (versions that use the X3201 chipset)
- Jaton XpressNet (Davicom DM9102)
- Kingston KNE100TX (21143, MII)
- Kingston KNE110TX (PNIC 82c169)
- LinkSys LNE100TX (PNIC 82c168, 82c169)
- LinkSys LNE100TX v2.0 (PNIC II 82c115)
- LinkSys LNE100TX v4.0/4.1 (ADMtek AN985 Centaur-P)
- Matrox FastNIC 10/100 (PNIC 82c168, 82c169)
- Melco LGY-PCI-TXL
- Microsoft MN-120 10/100 CardBus (ADMTek Centaur-C)
- Microsoft MN-130 10/100 PCI (ADMTek Centaur-P)
- NDC SOHOware SFA110A (98713A)
- NDC SOHOware SFA110A Rev B4 (98715AEC-C)
- NetGear FA310-TX Rev. D1, D2 or D3 (PNIC 82c169)
- Netgear FA511
- PlaneX FNW-3602-T (ADMtek AN985)
- SMC EZ Card 10/100 1233A-TX (ADMtek AN985)
- SVEC PN102-TX (98713)
- Xircom Cardbus Realport
- Xircom Cardbus Ethernet 10/100
- Xircom Cardbus Ethernet II 10/100
- dc%d: couldn't map ports/memory
- A fatal initialization error has occurred.
- dc%d: couldn't map interrupt
- A fatal initialization error has occurred.
- dc%d: watchdog timeout
- A packet was queued for transmission and a transmit command was issued,
but the device failed to acknowledge the transmission before a timeout
expired. This can happen if the device is unable to deliver interrupts for
some reason, of if there is a problem with the network connection (cable
or network equipment) that results in a loss of link.
- dc%d: no memory for rx list
- The driver failed to allocate an mbuf for the receiver ring.
- dc%d: TX underrun -- increasing TX threshold
- The device generated a transmit underrun error while attempting to DMA and
transmit a packet. This happens if the host is not able to DMA the packet
data into the NIC's FIFO fast enough. The driver will dynamically increase
the transmit start threshold so that more data must be DMAed into the FIFO
before the NIC will start transmitting it onto the wire.
- dc%d: TX underrun -- using store and forward mode
- The device continued to generate transmit underruns even after all
possible transmit start threshold settings had been tried, so the driver
programmed the chip for store and forward mode. In this mode, the NIC will
not begin transmission until the entire packet has been transferred into
its FIFO memory.
- dc%d: chip is in D3 power state -- setting to D0
- This message applies only to adapters which support power management. Some
operating systems place the controller in low power mode when shutting
down, and some PCI BIOSes fail to bring the chip out of this state before
configuring it. The controller loses all of its PCI configuration in the
D3 state, so if the BIOS does not set it back to full power mode in time,
it will not be able to configure it correctly. The driver tries to detect
this condition and bring the adapter back to the D0 (full power) state,
but this may not be enough to return the driver to a fully operational
condition. If you see this message at boot time and the driver fails to
attach the device as a network interface, you will have to perform a
second warm boot to have the device properly configured.
Note that this condition only occurs when warm booting from
another operating system. If you power down your system prior to booting
FreeBSD, the card should be configured
correctly.
altq(4),
arp(4),
miibus(4),
netintro(4),
ng_ether(4),
polling(4),
vlan(4),
ifconfig(8)
ADMtek AL981, AL983 and AL985
data sheets,
http://www.admtek.com.tw.
ASIX Electronics AX88140A and
AX88141 data sheets,
http://www.asix.com.tw.
Davicom DM9102 data
sheet,
http://www.davicom.com.tw/userfile/24247/DM9102H-DS-F01-021508.pdf.
Intel 21143 Hardware Reference
Manual,
http://developer.intel.com.
Macronix 98713/A, 98715/A and
98725 data sheets,
http://www.macronix.com.
Macronix 98713/A and 98715/A
app notes,
http://www.macronix.com.
The dc
device driver first appeared in
FreeBSD 4.0.
The Macronix application notes claim that in order to put the chips in normal
operation, the driver must write a certain magic number into the CSR16
register. The numbers are documented in the app notes, but the exact meaning
of the bits is not.
The 98713A seems to have a problem with 10Mbps full duplex mode.
The transmitter works but the receiver tends to produce many unexplained
errors leading to very poor overall performance. The 98715A does not exhibit
this problem. All other modes on the 98713A seem to work correctly.
The original 82c168 PNIC chip has built in NWAY support which is
used on certain early LinkSys LNE100TX and Matrox FastNIC cards, however it
is horribly broken and difficult to use reliably. Consequently,
autonegotiation is not currently supported for this chipset: the driver
defaults the NIC to 10baseT half duplex, and it is up to the operator to
manually select a different mode if necessary. (Later cards use an external
MII transceiver to implement NWAY autonegotiation and work correctly.)
The dc
driver programs 82c168 and 82c169
PNIC chips to use the store and forward setting for the transmit start
threshold by default. This is to work around problems with some NIC/PCI bus
combinations where the PNIC can transmit corrupt frames when operating at
100Mbps, probably due to PCI DMA burst transfer errors.
The 82c168 and 82c169 PNIC chips also have a receiver bug that
sometimes manifests during periods of heavy receive and transmit activity,
where the chip will improperly DMA received frames to the host. The chips
appear to upload several kilobytes of garbage data along with the received
frame data, dirtying several RX buffers instead of just the expected one.
The dc
driver detects this condition and will
salvage the frame; however, it incurs a serious performance penalty in the
process.
The PNIC chips also sometimes generate a transmit underrun error
when the driver attempts to download the receiver filter setup frame, which
can result in the receive filter being incorrectly programmed. The
dc
driver will watch for this condition and requeue
the setup frame until it is transferred successfully.
The ADMtek AL981 chip (and possibly the AN985 as well) has been
observed to sometimes wedge on transmit: this appears to happen when the
driver queues a sequence of frames which cause it to wrap from the end of
the transmit descriptor ring back to the beginning. The
dc
driver attempts to avoid this condition by not
queuing any frames past the end of the transmit ring during a single
invocation of the dc_start
() routine. This
workaround has a negligible impact on transmit performance.