xref: /OK3568_Linux_fs/kernel/Documentation/networking/device_drivers/fddi/defza.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun.. SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun=====================================================
4*4882a593SmuzhiyunNotes on the DEC FDDIcontroller 700 (DEFZA-xx) driver
5*4882a593Smuzhiyun=====================================================
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun:Version: v.1.1.4
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9*4882a593Smuzhiyun
10*4882a593SmuzhiyunDEC FDDIcontroller 700 is DEC's first-generation TURBOchannel FDDI
11*4882a593Smuzhiyunnetwork card, designed in 1990 specifically for the DECstation 5000
12*4882a593Smuzhiyunmodel 200 workstation.  The board is a single attachment station and
13*4882a593Smuzhiyunit was manufactured in two variations, both of which are supported.
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15*4882a593SmuzhiyunFirst is the SAS MMF DEFZA-AA option, the original design implementing
16*4882a593Smuzhiyunthe standard MMF-PMD, however with a pair of ST connectors rather than
17*4882a593Smuzhiyunthe usual MIC connector.  The other one is the SAS ThinWire/STP DEFZA-CA
18*4882a593Smuzhiyunoption, denoted 700-C, with the network medium selectable by a switch
19*4882a593Smuzhiyunbetween the DEC proprietary ThinWire-PMD using a BNC connector and the
20*4882a593Smuzhiyunstandard STP-PMD using a DE-9F connector.  This option can interface to
21*4882a593Smuzhiyuna DECconcentrator 500 device and, in the case of the STP-PMD, also other
22*4882a593SmuzhiyunFDDI equipment and was designed to make it easier to transition from
23*4882a593Smuzhiyunexisting IEEE 802.3 10BASE2 Ethernet and IEEE 802.5 Token Ring networks
24*4882a593Smuzhiyunby providing means to reuse existing cabling.
25*4882a593Smuzhiyun
26*4882a593SmuzhiyunThis driver handles any number of cards installed in a single system.
27*4882a593SmuzhiyunThey get fddi0, fddi1, etc. interface names assigned in the order of
28*4882a593Smuzhiyunincreasing TURBOchannel slot numbers.
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30*4882a593SmuzhiyunThe board only supports DMA on the receive side.  Transmission involves
31*4882a593Smuzhiyunthe use of PIO.  As a result under a heavy transmission load there will
32*4882a593Smuzhiyunbe a significant impact on system performance.
33*4882a593Smuzhiyun
34*4882a593SmuzhiyunThe board supports a 64-entry CAM for matching destination addresses.
35*4882a593SmuzhiyunTwo entries are preoccupied by the Directed Beacon and Ring Purger
36*4882a593Smuzhiyunmulticast addresses and the rest is used as a multicast filter.  An
37*4882a593Smuzhiyunall-multi mode is also supported for LLC frames and it is used if
38*4882a593Smuzhiyunrequested explicitly or if the CAM overflows.  The promiscuous mode
39*4882a593Smuzhiyunsupports separate enables for LLC and SMT frames, but this driver
40*4882a593Smuzhiyundoesn't support changing them individually.
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42*4882a593Smuzhiyun
43*4882a593SmuzhiyunKnown problems:
44*4882a593Smuzhiyun
45*4882a593SmuzhiyunNone.
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48*4882a593SmuzhiyunTo do:
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50*4882a593Smuzhiyun5. MAC address change.  The card does not support changing the Media
51*4882a593Smuzhiyun   Access Controller's address registers but a similar effect can be
52*4882a593Smuzhiyun   achieved by adding an alias to the CAM.  There is no way to disable
53*4882a593Smuzhiyun   matching against the original address though.
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun7. Queueing incoming/outgoing SMT frames in the driver if the SMT
56*4882a593Smuzhiyun   receive/RMC transmit ring is full. (?)
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun8. Retrieving/reporting FDDI/SNMP stats.
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60*4882a593Smuzhiyun
61*4882a593SmuzhiyunBoth success and failure reports are welcome.
62*4882a593Smuzhiyun
63*4882a593SmuzhiyunMaciej W. Rozycki  <macro@linux-mips.org>
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