1 .. SPDX-License-Identifier: GPL-2.0
2 .. include:: <isonum.txt>
3
4 ==============================================
5 Adaptec AHA-1520/1522 SCSI driver for Linux (a
6 ==============================================
7
8 Copyright |copy| 1993-1999 Jürgen Fischer <fis
9
10 TC1550 patches by Luuk van Dijk (ldz@xs4all.nl
11
12
13 In Revision 2 the driver was modified a lot (e
14 bottom-half handler complete()).
15
16 The driver is much cleaner now, has support fo
17 error handling code in 2.3, produced less cpu
18 less polling loops), has slightly higher throu
19 least on my ancient test box; a i486/33Mhz/20M
20
21
22 Configuration Arguments
23 =======================
24
25 ============ ================================
26 IOPORT base io address
27 IRQ interrupt level
28 SCSI_ID scsi id of controller
29 RECONNECT allow targets to disconnect from
30 PARITY enable parity checking
31 SYNCHRONOUS enable synchronous transfers
32 DELAY: bus reset delay
33 EXT_TRANS: enable extended translation
34 (see NOTES)
35 ============ ================================
36
37 Compile Time Configuration
38 ==========================
39
40 (go into AHA152X in drivers/scsi/Makefile):
41
42 - DAUTOCONF
43 use configuration the controller reports (
44
45 - DSKIP_BIOSTEST
46 Don't test for BIOS signature (AHA-1510 or
47
48 - DSETUP0="{ IOPORT, IRQ, SCSI_ID, RECONNECT,
49 override for the first controller
50
51 - DSETUP1="{ IOPORT, IRQ, SCSI_ID, RECONNECT,
52 override for the second controller
53
54 - DAHA152X_DEBUG
55 enable debugging output
56
57 - DAHA152X_STAT
58 enable some statistics
59
60
61 LILO Command Line Options
62 =========================
63
64 ::
65
66 aha152x=<IOPORT>[,<IRQ>[,<SCSI-ID>[,<RECON
67
68 The normal configuration can be overridden by
69 When you do this, the BIOS test is skipped. E
70 valid (known). Don't use values that aren't
71 operation. If you think that you need other
72 For two controllers use the aha152x statement
73
74
75 Symbols for Module Configuration
76 ================================
77
78 Choose from 2 alternatives:
79
80 1. specify everything (old)::
81
82 aha152x=IOPORT,IRQ,SCSI_ID,RECONNECT,PARIT
83
84 configuration override for first controller
85
86 ::
87
88 aha152x1=IOPORT,IRQ,SCSI_ID,RECONNECT,PARI
89
90 configuration override for second controller
91
92 2. specify only what you need to (irq or io is
93
94 io=IOPORT0[,IOPORT1]
95 IOPORT for first and second controller
96
97 irq=IRQ0[,IRQ1]
98 IRQ for first and second controller
99
100 scsiid=SCSIID0[,SCSIID1]
101 SCSIID for first and second controller
102
103 reconnect=RECONNECT0[,RECONNECT1]
104 allow targets to disconnect for first and se
105
106 parity=PAR0[PAR1]
107 use parity for first and second controller
108
109 sync=SYNCHRONOUS0[,SYNCHRONOUS1]
110 enable synchronous transfers for first and s
111
112 delay=DELAY0[,DELAY1]
113 reset DELAY for first and second controller
114
115 exttrans=EXTTRANS0[,EXTTRANS1]
116 enable extended translation for first and se
117
118
119 If you use both alternatives the first will be
120
121
122 Notes on EXT_TRANS
123 ==================
124
125 SCSI uses block numbers to address blocks/sect
126 The BIOS uses a cylinder/head/sector addressin
127 scheme instead. DOS expects a BIOS or driver
128 C/H/S addressing.
129
130 The number of cylinders/heads/sectors is calle
131 as base for requests in C/H/S addressing. SCS
132 total capacity of disks in blocks (sectors).
133
134 Therefore the SCSI BIOS/DOS driver has to calc
135 geometry just to be able to support that addre
136 returned by the SCSI BIOS is a pure calculatio
137 do with the real/physical geometry of the disk
138 irrelevant anyway).
139
140 Basically this has no impact at all on Linux,
141 instead of C/H/S addressing. Unfortunately C/
142 in the partition table and therefore every ope
143 the right geometry to be able to interpret it.
144
145 Moreover there are certain limitations to the
146 namely the address space is limited to up to 2
147 and a maximum of 1023 cylinders.
148
149 The AHA-1522 BIOS calculates the geometry by f
150 to 64, the number of sectors to 32 and by calc
151 cylinders by dividing the capacity reported by
152 This is considered to be the default translati
153
154 With respect to the limit of 1023 cylinders us
155 address the first GB of your disk in the parti
156 BIOSes of some newer controllers based on the
157 extended translation. This means that the BIO
158 63 for sectors and then divides the capacity o
159 (about 8 MB), as soon it sees a disk greater t
160 in a maximum of about 8 GB addressable diskspa
161 (but there are already bigger disks out there
162
163 To make it even more complicated the translati
164 not be configurable in certain BIOS setups.
165
166 This driver does some more or less failsafe gu
167 geometry right in most cases:
168
169 - for disks<1GB: use default translation (C/32
170
171 - for disks>1GB:
172
173 - take current geometry from the partition t
174 (using scsicam_bios_param and accept only
175 ie. either (C/32/64) or (C/63/255)). This
176 even if it's not enabled in the driver.
177
178 - if that fails, take extended translation i
179 kernel or module parameter, otherwise take
180 ask the user for verification. This might
181 disks.
182
183
184 References Used
185 ===============
186
187 "AIC-6260 SCSI Chip Specification", Adaptec C
188
189 "SCSI COMPUTER SYSTEM INTERFACE - 2 (SCSI-2)"
190
191 "Writing a SCSI device driver for Linux", Rik
192
193 "Kernel Hacker's Guide", Michael K. Johnson (
194
195 "Adaptec 1520/1522 User's Guide", Adaptec Cor
196
197 Michael K. Johnson (johnsonm@sunsite.unc.edu)
198
199 Drew Eckhardt (drew@cs.colorado.edu)
200
201 Eric Youngdale (eric@andante.org)
202
203 special thanks to Eric Youngdale for the free
204 documentation on the chip.
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