.\" $OpenBSD: dc.4,v 1.21 2001/04/23 15:30:25 aaron Exp $ .\" .\" Copyright (c) 1997, 1998, 1999 .\" Bill Paul . All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by Bill Paul. .\" 4. Neither the name of the author nor the names of any co-contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD .\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF .\" THE POSSIBILITY OF SUCH DAMAGE. .\" .\" $FreeBSD: src/share/man/man4/dc.4,v 1.1 1999/12/04 17:41:24 wpaul Exp $ .\" .Dd November 20, 1999 .Dt DC 4 .Os .Sh NAME .Nm dc .Nd DEC/Intel 21143 and clone 10/100 Ethernet driver .Sh SYNOPSIS .Cd "dc* at pci? dev ? function ?" .Sh DESCRIPTION The .Nm driver provides support for several PCI and CardBus Fast Ethernet adapters and embedded controllers based on the following chipsets: .Pp .Bl -bullet -compact -offset indent .It DEC/Intel 21143 PCI and CardBus .It Macronix 98713, 98713A, 98715, 98715A, 98725, 98727, and 98732 .It Davicom DM9100, DM9102, and DM9102A .It ASIX Electronics AX88140A and AX88141 .It ADMtek AL981 Comet PCI and AN983 Centaur-P PCI .It ADMtek AN985 Centaur-C CardBus .It Lite-On 82c168 and 82c169 PNIC .It Lite-On/Macronix 82c115 PNIC II .It Xircom X3201-based CardBus .El .Pp All of these chips 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. .Pp 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 .Nm driver does its best to provide generalized support for all of these chipsets in order to keep special case code to a minimum. .Pp These chips are used by many vendors which makes it difficult provide a complete list of all supported cards. The following NICs are known to work with the .Nm driver at this time: .Pp .Bl -bullet -compact -offset indent .It Digital DE500-BA 10/100 (21143, non-MII) .It Built in DE500-BA on DEC Alpha workstations (21143, non-MII) .It Built in Ethernet on LinkSys EtherFast 10/100 Instant GigaDrive (DM9102, MII) .It Kingston KNE100TX (21143, MII) .It D-Link DFE-570TX (21143, MII, quad port) .It NDC SOHOware SFA110A (98713A) .It NDC SOHOware SFA110A Rev B4 (98715AEC-C) .It SVEC PN102-TX (98713) .It CNet Pro120A (98715A or 98713A) and CNet Pro120B (98715) .It Compex RL100-TX (98713 or 98713A) .It LinkSys LNE100TX (PNIC 82c168, 82c169) .It NetGear FA310-TX Rev. D1, D2 or D3 (PNIC 82c169) .It Matrox FastNIC 10/100 (PNIC 82c168, 82c169) .It Kingston KNE110TX (PNIC 82c169) .It LinkSys LNE100TX v2.0 (PNIC II 82c115) .It Jaton XpressNet (Davicom DM9102) .It Alfa Inc GFC2204 (ASIX AX88140A) .It CNet Pro110B (ASIX AX88140A) .It LinkSys LNE100TX v4.x (ADMtek AN983 Centaur-P) .It Xircom CardBus, including RealPort models (Xircom X3201) .It IBM EtherJet 10/100 CardBus (Intel 21143) .It Accton EN1217 (98715) and EN2242 (ADMtek Centaur) .It Mototech ME316 (ADMtek Centaur) .El .Pp The .Nm driver supports the following media types: .Pp .Bl -tag -width xxxxxxxxxxxxxxxxxxxx .It autoselect Enable autoselection of the media type and options. The user can manually override the autoselected mode by adding media options to the .Xr hostname.if 5 file. .Pp Note: the built-in NWAY autonegotiation on the original PNIC 82c168 chip is horribly broken and is not supported by the .Nm driver at this time: the chip will operate in any speed or duplex mode, however these must be set manually. The original 82c168 appears on very early revisions of the LinkSys LNE100TX and Matrox FastNIC. .It 10baseT/UTP Set 10Mbps operation. The .Ar mediaopt option can also be used to enable .Ar full-duplex operation. Not specifying .Ar full duplex implies .Ar half-duplex mode. .It 100baseTX Set 100Mbps (Fast Ethernet) operation. The .Ar mediaopt option can also be used to enable .Ar full-duplex operation. Not specifying .Ar full duplex implies .Ar half-duplex mode. .El .Pp The .Nm driver supports the following media options: .Pp .Bl -tag -width xxxxxxxxxxxxxxxxxxxx .It full-duplex Force full duplex operation. The interface will operate in half duplex mode if this media option is not specified. .El .Pp 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 .Xr ifconfig 8 . .Sh DIAGNOSTICS .Bl -diag .It "dc%d: couldn't map ports/memory" A fatal initialization error has occurred. .It "dc%d: couldn't map interrupt" A fatal initialization error has occurred. .It "dc%d: watchdog timeout" A packet was queued for transmission and a transmit command was issued, however 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, or if there is a problem with the network connection (cable). .It "dc%d: no memory for rx list" The driver failed to allocate an mbuf for the receiver ring. .It "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. .It "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. .It "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 won't 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. .Pp Note that this condition only occurs when warm booting from another operating system. If you power down your system prior to booting .Ox , the card should be configured correctly. .El .Sh SEE ALSO .Xr arp 4 , .Xr netintro 4 , .Xr ifconfig 8 .Rs .%T ADMtek AL981 and AL983 data sheets .%O http://www.admtek.com.tw .Re .Rs .%T ASIX Electronics AX88140A and AX88141 data sheets .%O http://www.asix.com.tw .Re .Rs .%T Davicom DM9102 data sheet .%O http://www.davicom8.com .Re .Rs .%T Intel 21143 Hardware Reference Manual .%O http://developer.intel.com .Re .Rs .%T Macronix 98713/A, 98715/A and 98725 data sheets .%O http://www.macronix.com .Re .Rs .%T Macronix 98713/A and 98715/A app notes .%O http://www.macronix.com .Re .Sh HISTORY The .Nm device driver first appeared in .Fx 4.0 . .Ox support was added in .Ox 2.7 . .Sh AUTHORS The .Nm driver was written by Bill Paul and ported to .Ox by Aaron Campbell . .Sh BUGS 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. .Pp 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. .Pp 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's 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.) .Pp The .Nm 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. .Pp 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 .Nm driver detects this condition and will salvage the frame, however it incurs a serious performance penalty in the process. .Pp 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 .Nm driver will watch for this condition and requeue the setup frame until it is transferred successfully. .Pp The ADMtek AL981 chip (and possibly the AN983 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 .Nm driver attempts to avoid this condition by not queuing any frames past the end of the transmit ring during a single invocation of the .Fn dc_start routine. This workaround has a negligible impact on transmit performance. .Pp The .Fn mii_tick function does not currently run for ASIX boards, meaning cable disconnects and reconnects can go unnoticed. The AX88140A and AX88141 data sheets indicate that they don't have RX or TX state registers (the bits are reserved). Therefore, we can't seem to reliably detect when the adapter is idle. .Pp The Davicom interfaces require a grossly high PCI latency timer value to function properly. This means when a Davicom adapter is present in the machine, it is given an unfairly high amount of bandwidth on the PCI bus, unnecessarily taking time away from other devices. Therefore, Davicom network cards are not recommended for use with .Ox . Be careful; some motherboards have Davicom interfaces built-in.