| .. SPDX-License-Identifier: GPL-2.0 |
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| ===================================================== |
| Notes on the DEC FDDIcontroller 700 (DEFZA-xx) driver |
| ===================================================== |
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| :Version: v.1.1.4 |
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| DEC FDDIcontroller 700 is DEC's first-generation TURBOchannel FDDI |
| network card, designed in 1990 specifically for the DECstation 5000 |
| model 200 workstation. The board is a single attachment station and |
| it was manufactured in two variations, both of which are supported. |
| |
| First is the SAS MMF DEFZA-AA option, the original design implementing |
| the standard MMF-PMD, however with a pair of ST connectors rather than |
| the usual MIC connector. The other one is the SAS ThinWire/STP DEFZA-CA |
| option, denoted 700-C, with the network medium selectable by a switch |
| between the DEC proprietary ThinWire-PMD using a BNC connector and the |
| standard STP-PMD using a DE-9F connector. This option can interface to |
| a DECconcentrator 500 device and, in the case of the STP-PMD, also other |
| FDDI equipment and was designed to make it easier to transition from |
| existing IEEE 802.3 10BASE2 Ethernet and IEEE 802.5 Token Ring networks |
| by providing means to reuse existing cabling. |
| |
| This driver handles any number of cards installed in a single system. |
| They get fddi0, fddi1, etc. interface names assigned in the order of |
| increasing TURBOchannel slot numbers. |
| |
| The board only supports DMA on the receive side. Transmission involves |
| the use of PIO. As a result under a heavy transmission load there will |
| be a significant impact on system performance. |
| |
| The board supports a 64-entry CAM for matching destination addresses. |
| Two entries are preoccupied by the Directed Beacon and Ring Purger |
| multicast addresses and the rest is used as a multicast filter. An |
| all-multi mode is also supported for LLC frames and it is used if |
| requested explicitly or if the CAM overflows. The promiscuous mode |
| supports separate enables for LLC and SMT frames, but this driver |
| doesn't support changing them individually. |
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| Known problems: |
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| None. |
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| To do: |
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| 5. MAC address change. The card does not support changing the Media |
| Access Controller's address registers but a similar effect can be |
| achieved by adding an alias to the CAM. There is no way to disable |
| matching against the original address though. |
| |
| 7. Queueing incoming/outgoing SMT frames in the driver if the SMT |
| receive/RMC transmit ring is full. (?) |
| |
| 8. Retrieving/reporting FDDI/SNMP stats. |
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| |
| Both success and failure reports are welcome. |
| |
| Maciej W. Rozycki <macro@orcam.me.uk> |
