Root/Documentation/networking/de4x5.txt

1    Originally, this driver was written for the Digital Equipment
2    Corporation series of EtherWORKS Ethernet cards:
3
4        DE425 TP/COAX EISA
5    DE434 TP PCI
6    DE435 TP/COAX/AUI PCI
7    DE450 TP/COAX/AUI PCI
8    DE500 10/100 PCI Fasternet
9
10    but it will now attempt to support all cards which conform to the
11    Digital Semiconductor SROM Specification. The driver currently
12    recognises the following chips:
13
14        DC21040 (no SROM)
15    DC21041[A]
16    DC21140[A]
17    DC21142
18    DC21143
19
20    So far the driver is known to work with the following cards:
21
22        KINGSTON
23    Linksys
24    ZNYX342
25    SMC8432
26    SMC9332 (w/new SROM)
27    ZNYX31[45]
28    ZNYX346 10/100 4 port (can act as a 10/100 bridge!)
29
30    The driver has been tested on a relatively busy network using the DE425,
31    DE434, DE435 and DE500 cards and benchmarked with 'ttcp': it transferred
32    16M of data to a DECstation 5000/200 as follows:
33
34                TCP UDP
35             TX RX TX RX
36    DE425 1030k 997k 1170k 1128k
37    DE434 1063k 995k 1170k 1125k
38    DE435 1063k 995k 1170k 1125k
39    DE500 1063k 998k 1170k 1125k in 10Mb/s mode
40
41    All values are typical (in kBytes/sec) from a sample of 4 for each
42    measurement. Their error is +/-20k on a quiet (private) network and also
43    depend on what load the CPU has.
44
45    =========================================================================
46
47    The ability to load this driver as a loadable module has been included
48    and used extensively during the driver development (to save those long
49    reboot sequences). Loadable module support under PCI and EISA has been
50    achieved by letting the driver autoprobe as if it were compiled into the
51    kernel. Do make sure you're not sharing interrupts with anything that
52    cannot accommodate interrupt sharing!
53
54    To utilise this ability, you have to do 8 things:
55
56    0) have a copy of the loadable modules code installed on your system.
57    1) copy de4x5.c from the /linux/drivers/net directory to your favourite
58    temporary directory.
59    2) for fixed autoprobes (not recommended), edit the source code near
60    line 5594 to reflect the I/O address you're using, or assign these when
61    loading by:
62
63                   insmod de4x5 io=0xghh where g = bus number
64                                                hh = device number
65
66       NB: autoprobing for modules is now supported by default. You may just
67           use:
68
69                   insmod de4x5
70
71           to load all available boards. For a specific board, still use
72       the 'io=?' above.
73    3) compile de4x5.c, but include -DMODULE in the command line to ensure
74    that the correct bits are compiled (see end of source code).
75    4) if you are wanting to add a new card, goto 5. Otherwise, recompile a
76    kernel with the de4x5 configuration turned off and reboot.
77    5) insmod de4x5 [io=0xghh]
78    6) run the net startup bits for your new eth?? interface(s) manually
79    (usually /etc/rc.inet[12] at boot time).
80    7) enjoy!
81
82    To unload a module, turn off the associated interface(s)
83    'ifconfig eth?? down' then 'rmmod de4x5'.
84
85    Automedia detection is included so that in principle you can disconnect
86    from, e.g. TP, reconnect to BNC and things will still work (after a
87    pause whilst the driver figures out where its media went). My tests
88    using ping showed that it appears to work....
89
90    By default, the driver will now autodetect any DECchip based card.
91    Should you have a need to restrict the driver to DIGITAL only cards, you
92    can compile with a DEC_ONLY define, or if loading as a module, use the
93    'dec_only=1' parameter.
94
95    I've changed the timing routines to use the kernel timer and scheduling
96    functions so that the hangs and other assorted problems that occurred
97    while autosensing the media should be gone. A bonus for the DC21040
98    auto media sense algorithm is that it can now use one that is more in
99    line with the rest (the DC21040 chip doesn't have a hardware timer).
100    The downside is the 1 'jiffies' (10ms) resolution.
101
102    IEEE 802.3u MII interface code has been added in anticipation that some
103    products may use it in the future.
104
105    The SMC9332 card has a non-compliant SROM which needs fixing - I have
106    patched this driver to detect it because the SROM format used complies
107    to a previous DEC-STD format.
108
109    I have removed the buffer copies needed for receive on Intels. I cannot
110    remove them for Alphas since the Tulip hardware only does longword
111    aligned DMA transfers and the Alphas get alignment traps with non
112    longword aligned data copies (which makes them really slow). No comment.
113
114    I have added SROM decoding routines to make this driver work with any
115    card that supports the Digital Semiconductor SROM spec. This will help
116    all cards running the dc2114x series chips in particular. Cards using
117    the dc2104x chips should run correctly with the basic driver. I'm in
118    debt to <mjacob@feral.com> for the testing and feedback that helped get
119    this feature working. So far we have tested KINGSTON, SMC8432, SMC9332
120    (with the latest SROM complying with the SROM spec V3: their first was
121    broken), ZNYX342 and LinkSys. ZNYX314 (dual 21041 MAC) and ZNYX 315
122    (quad 21041 MAC) cards also appear to work despite their incorrectly
123    wired IRQs.
124
125    I have added a temporary fix for interrupt problems when some SCSI cards
126    share the same interrupt as the DECchip based cards. The problem occurs
127    because the SCSI card wants to grab the interrupt as a fast interrupt
128    (runs the service routine with interrupts turned off) vs. this card
129    which really needs to run the service routine with interrupts turned on.
130    This driver will now add the interrupt service routine as a fast
131    interrupt if it is bounced from the slow interrupt. THIS IS NOT A
132    RECOMMENDED WAY TO RUN THE DRIVER and has been done for a limited time
133    until people sort out their compatibility issues and the kernel
134    interrupt service code is fixed. YOU SHOULD SEPARATE OUT THE FAST
135    INTERRUPT CARDS FROM THE SLOW INTERRUPT CARDS to ensure that they do not
136    run on the same interrupt. PCMCIA/CardBus is another can of worms...
137
138    Finally, I think I have really fixed the module loading problem with
139    more than one DECchip based card. As a side effect, I don't mess with
140    the device structure any more which means that if more than 1 card in
141    2.0.x is installed (4 in 2.1.x), the user will have to edit
142    linux/drivers/net/Space.c to make room for them. Hence, module loading
143    is the preferred way to use this driver, since it doesn't have this
144    limitation.
145
146    Where SROM media detection is used and full duplex is specified in the
147    SROM, the feature is ignored unless lp->params.fdx is set at compile
148    time OR during a module load (insmod de4x5 args='eth??:fdx' [see
149    below]). This is because there is no way to automatically detect full
150    duplex links except through autonegotiation. When I include the
151    autonegotiation feature in the SROM autoconf code, this detection will
152    occur automatically for that case.
153
154    Command line arguments are now allowed, similar to passing arguments
155    through LILO. This will allow a per adapter board set up of full duplex
156    and media. The only lexical constraints are: the board name (dev->name)
157    appears in the list before its parameters. The list of parameters ends
158    either at the end of the parameter list or with another board name. The
159    following parameters are allowed:
160
161            fdx for full duplex
162        autosense to set the media/speed; with the following
163                   sub-parameters:
164               TP, TP_NW, BNC, AUI, BNC_AUI, 100Mb, 10Mb, AUTO
165
166    Case sensitivity is important for the sub-parameters. They *must* be
167    upper case. Examples:
168
169        insmod de4x5 args='eth1:fdx autosense=BNC eth0:autosense=100Mb'.
170
171    For a compiled in driver, in linux/drivers/net/CONFIG, place e.g.
172    DE4X5_OPTS = -DDE4X5_PARM='"eth0:fdx autosense=AUI eth2:autosense=TP"'
173
174    Yes, I know full duplex isn't permissible on BNC or AUI; they're just
175    examples. By default, full duplex is turned off and AUTO is the default
176    autosense setting. In reality, I expect only the full duplex option to
177    be used. Note the use of single quotes in the two examples above and the
178    lack of commas to separate items.
179

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