1.. SPDX-License-Identifier: GPL-2.0 2 3===================================================== 4Notes on the DEC FDDIcontroller 700 (DEFZA-xx) driver 5===================================================== 6 7:Version: v.1.1.4 8 9 10DEC FDDIcontroller 700 is DEC's first-generation TURBOchannel FDDI 11network card, designed in 1990 specifically for the DECstation 5000 12model 200 workstation. The board is a single attachment station and 13it was manufactured in two variations, both of which are supported. 14 15First is the SAS MMF DEFZA-AA option, the original design implementing 16the standard MMF-PMD, however with a pair of ST connectors rather than 17the usual MIC connector. The other one is the SAS ThinWire/STP DEFZA-CA 18option, denoted 700-C, with the network medium selectable by a switch 19between the DEC proprietary ThinWire-PMD using a BNC connector and the 20standard STP-PMD using a DE-9F connector. This option can interface to 21a DECconcentrator 500 device and, in the case of the STP-PMD, also other 22FDDI equipment and was designed to make it easier to transition from 23existing IEEE 802.3 10BASE2 Ethernet and IEEE 802.5 Token Ring networks 24by providing means to reuse existing cabling. 25 26This driver handles any number of cards installed in a single system. 27They get fddi0, fddi1, etc. interface names assigned in the order of 28increasing TURBOchannel slot numbers. 29 30The board only supports DMA on the receive side. Transmission involves 31the use of PIO. As a result under a heavy transmission load there will 32be a significant impact on system performance. 33 34The board supports a 64-entry CAM for matching destination addresses. 35Two entries are preoccupied by the Directed Beacon and Ring Purger 36multicast addresses and the rest is used as a multicast filter. An 37all-multi mode is also supported for LLC frames and it is used if 38requested explicitly or if the CAM overflows. The promiscuous mode 39supports separate enables for LLC and SMT frames, but this driver 40doesn't support changing them individually. 41 42 43Known problems: 44 45None. 46 47 48To do: 49 505. MAC address change. The card does not support changing the Media 51 Access Controller's address registers but a similar effect can be 52 achieved by adding an alias to the CAM. There is no way to disable 53 matching against the original address though. 54 557. Queueing incoming/outgoing SMT frames in the driver if the SMT 56 receive/RMC transmit ring is full. (?) 57 588. Retrieving/reporting FDDI/SNMP stats. 59 60 61Both success and failure reports are welcome. 62 63Maciej W. Rozycki <macro@linux-mips.org> 64