diff options
Diffstat (limited to 'Documentation/networking/defza.rst')
| -rw-r--r-- | Documentation/networking/defza.rst | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/Documentation/networking/defza.rst b/Documentation/networking/defza.rst new file mode 100644 index 000000000000..73c2f793ea26 --- /dev/null +++ b/Documentation/networking/defza.rst @@ -0,0 +1,63 @@ +.. SPDX-License-Identifier: GPL-2.0 + +===================================================== +Notes on the DEC FDDIcontroller 700 (DEFZA-xx) driver +===================================================== + +:Version: v.1.1.4 + + +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. + + +Known problems: + +None. + + +To do: + +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. + + +Both success and failure reports are welcome. + +Maciej W. Rozycki <macro@linux-mips.org> |