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1 The Linux NCR53C8XX/SYM53C8XX drivers README file
2
3 Written by Gerard Roudier <groudier@free.fr>
4 21 Rue Carnot
5 95170 DEUIL LA BARRE - FRANCE
6
7 29 May 1999
8 ===============================================================================
9
10 1. Introduction
11 2. Supported chips and SCSI features
12 3. Advantages of the enhanced 896 driver
13 3.1 Optimized SCSI SCRIPTS
14 3.2 New features of the SYM53C896 (64 bit PCI dual LVD SCSI controller)
15 4. Memory mapped I/O versus normal I/O
16 5. Tagged command queueing
17 6. Parity checking
18 7. Profiling information
19 8. Control commands
20 8.1 Set minimum synchronous period
21 8.2 Set wide size
22 8.3 Set maximum number of concurrent tagged commands
23 8.4 Set order type for tagged command
24 8.5 Set debug mode
25 8.6 Clear profile counters
26 8.7 Set flag (no_disc)
27 8.8 Set verbose level
28 8.9 Reset all logical units of a target
29 8.10 Abort all tasks of all logical units of a target
30 9. Configuration parameters
31 10. Boot setup commands
32 10.1 Syntax
33 10.2 Available arguments
34 10.2.1 Master parity checking
35 10.2.2 Scsi parity checking
36 10.2.3 Scsi disconnections
37 10.2.4 Special features
38 10.2.5 Ultra SCSI support
39 10.2.6 Default number of tagged commands
40 10.2.7 Default synchronous period factor
41 10.2.8 Negotiate synchronous with all devices
42 10.2.9 Verbosity level
43 10.2.10 Debug mode
44 10.2.11 Burst max
45 10.2.12 LED support
46 10.2.13 Max wide
47 10.2.14 Differential mode
48 10.2.15 IRQ mode
49 10.2.16 Reverse probe
50 10.2.17 Fix up PCI configuration space
51 10.2.18 Serial NVRAM
52 10.2.19 Check SCSI BUS
53 10.2.20 Exclude a host from being attached
54 10.2.21 Suggest a default SCSI id for hosts
55 10.2.22 Enable use of IMMEDIATE ARBITRATION
56 10.3 Advised boot setup commands
57 10.4 PCI configuration fix-up boot option
58 10.5 Serial NVRAM support boot option
59 10.6 SCSI BUS checking boot option
60 10.7 IMMEDIATE ARBITRATION boot option
61 11. Some constants and flags of the ncr53c8xx.h header file
62 12. Installation
63 13. Architecture dependent features
64 14. Known problems
65 14.1 Tagged commands with Iomega Jaz device
66 14.2 Device names change when another controller is added
67 14.3 Using only 8 bit devices with a WIDE SCSI controller.
68 14.4 Possible data corruption during a Memory Write and Invalidate
69 14.5 IRQ sharing problems
70 15. SCSI problem troubleshooting
71 15.1 Problem tracking
72 15.2 Understanding hardware error reports
73 16. Synchronous transfer negotiation tables
74 16.1 Synchronous timings for 53C875 and 53C860 Ultra-SCSI controllers
75 16.2 Synchronous timings for fast SCSI-2 53C8XX controllers
76 17. Serial NVRAM support (by Richard Waltham)
77 17.1 Features
78 17.2 Symbios NVRAM layout
79 17.3 Tekram NVRAM layout
80 18. Support for Big Endian
81 18.1 Big Endian CPU
82 18.2 NCR chip in Big Endian mode of operations
83
84 ===============================================================================
85
86 1. Introduction
87
88 The initial Linux ncr53c8xx driver has been a port of the ncr driver from
89 FreeBSD that has been achieved in November 1995 by:
90 Gerard Roudier <groudier@free.fr>
91
92 The original driver has been written for 386bsd and FreeBSD by:
93 Wolfgang Stanglmeier <wolf@cologne.de>
94 Stefan Esser <se@mi.Uni-Koeln.de>
95
96 It is now available as a bundle of 2 drivers:
97
98 - ncr53c8xx generic driver that supports all the SYM53C8XX family including
99 the earliest 810 rev. 1, the latest 896 (2 channel LVD SCSI controller) and
100 the new 895A (1 channel LVD SCSI controller).
101 - sym53c8xx enhanced driver (a.k.a. 896 drivers) that drops support of oldest
102 chips in order to gain advantage of new features, as LOAD/STORE instructions
103 available since the 810A and hardware phase mismatch available with the
104 896 and the 895A.
105
106 You can find technical information about the NCR 8xx family in the
107 PCI-HOWTO written by Michael Will and in the SCSI-HOWTO written by
108 Drew Eckhardt.
109
110 Information about new chips is available at LSILOGIC web server:
111
112 http://www.lsilogic.com/
113
114 SCSI standard documentations are available at SYMBIOS ftp server:
115
116 ftp://ftp.symbios.com/
117
118 Useful SCSI tools written by Eric Youngdale are available at tsx-11:
119
120 ftp://tsx-11.mit.edu/pub/linux/ALPHA/scsi/scsiinfo-X.Y.tar.gz
121 ftp://tsx-11.mit.edu/pub/linux/ALPHA/scsi/scsidev-X.Y.tar.gz
122
123 These tools are not ALPHA but quite clean and work quite well.
124 It is essential you have the 'scsiinfo' package.
125
126 This short documentation describes the features of the generic and enhanced
127 drivers, configuration parameters and control commands available through
128 the proc SCSI file system read / write operations.
129
130 This driver has been tested OK with linux/i386, Linux/Alpha and Linux/PPC.
131
132 Latest driver version and patches are available at:
133
134 ftp://ftp.tux.org/pub/people/gerard-roudier
135 or
136 ftp://ftp.symbios.com/mirror/ftp.tux.org/pub/tux/roudier/drivers
137
138 I am not a native speaker of English and there are probably lots of
139 mistakes in this README file. Any help will be welcome.
140
141
142 2. Supported chips and SCSI features
143
144 The following features are supported for all chips:
145
146 Synchronous negotiation
147 Disconnection
148 Tagged command queuing
149 SCSI parity checking
150 Master parity checking
151
152 "Wide negotiation" is supported for chips that allow it. The
153 following table shows some characteristics of NCR 8xx family chips
154 and what drivers support them.
155
156 Supported by Supported by
157 On board the generic the enhanced
158 Chip SDMS BIOS Wide SCSI std. Max. sync driver driver
159 ---- --------- ---- --------- ---------- ------------ -------------
160 810 N N FAST10 10 MB/s Y N
161 810A N N FAST10 10 MB/s Y Y
162 815 Y N FAST10 10 MB/s Y N
163 825 Y Y FAST10 20 MB/s Y N
164 825A Y Y FAST10 20 MB/s Y Y
165 860 N N FAST20 20 MB/s Y Y
166 875 Y Y FAST20 40 MB/s Y Y
167 876 Y Y FAST20 40 MB/s Y Y
168 895 Y Y FAST40 80 MB/s Y Y
169 895A Y Y FAST40 80 MB/s Y Y
170 896 Y Y FAST40 80 MB/s Y Y
171 897 Y Y FAST40 80 MB/s Y Y
172 1510D Y Y FAST40 80 MB/s Y Y
173 1010 Y Y FAST80 160 MB/s N Y
174 1010_66* Y Y FAST80 160 MB/s N Y
175
176 * Chip supports 33MHz and 66MHz PCI buses.
177
178
179 Summary of other supported features:
180
181 Module: allow to load the driver
182 Memory mapped I/O: increases performance
183 Profiling information: read operations from the proc SCSI file system
184 Control commands: write operations to the proc SCSI file system
185 Debugging information: written to syslog (expert only)
186 Scatter / gather
187 Shared interrupt
188 Boot setup commands
189 Serial NVRAM: Symbios and Tekram formats
190
191
192 3. Advantages of the enhanced 896 driver
193
194 3.1 Optimized SCSI SCRIPTS.
195
196 The 810A, 825A, 875, 895, 896 and 895A support new SCSI SCRIPTS instructions
197 named LOAD and STORE that allow to move up to 1 DWORD from/to an IO register
198 to/from memory much faster that the MOVE MEMORY instruction that is supported
199 by the 53c7xx and 53c8xx family.
200 The LOAD/STORE instructions support absolute and DSA relative addressing
201 modes. The SCSI SCRIPTS had been entirely rewritten using LOAD/STORE instead
202 of MOVE MEMORY instructions.
203
204 3.2 New features of the SYM53C896 (64 bit PCI dual LVD SCSI controller)
205
206 The 896 and the 895A allows handling of the phase mismatch context from
207 SCRIPTS (avoids the phase mismatch interrupt that stops the SCSI processor
208 until the C code has saved the context of the transfer).
209 Implementing this without using LOAD/STORE instructions would be painful
210 and I didn't even want to try it.
211
212 The 896 chip supports 64 bit PCI transactions and addressing, while the
213 895A supports 32 bit PCI transactions and 64 bit addressing.
214 The SCRIPTS processor of these chips is not true 64 bit, but uses segment
215 registers for bit 32-63. Another interesting feature is that LOAD/STORE
216 instructions that address the on-chip RAM (8k) remain internal to the chip.
217
218 Due to the use of LOAD/STORE SCRIPTS instructions, this driver does not
219 support the following chips:
220 - SYM53C810 revision < 0x10 (16)
221 - SYM53C815 all revisions
222 - SYM53C825 revision < 0x10 (16)
223
224 4. Memory mapped I/O versus normal I/O
225
226 Memory mapped I/O has less latency than normal I/O. Since
227 linux-1.3.x, memory mapped I/O is used rather than normal I/O. Memory
228 mapped I/O seems to work fine on most hardware configurations, but
229 some poorly designed motherboards may break this feature.
230
231 The configuration option CONFIG_SCSI_NCR53C8XX_IOMAPPED forces the
232 driver to use normal I/O in all cases.
233
234
235 5. Tagged command queueing
236
237 Queuing more than 1 command at a time to a device allows it to perform
238 optimizations based on actual head positions and its mechanical
239 characteristics. This feature may also reduce average command latency.
240 In order to really gain advantage of this feature, devices must have
241 a reasonable cache size (No miracle is to be expected for a low-end
242 hard disk with 128 KB or less).
243 Some known SCSI devices do not properly support tagged command queuing.
244 Generally, firmware revisions that fix this kind of problems are available
245 at respective vendor web/ftp sites.
246 All I can say is that the hard disks I use on my machines behave well with
247 this driver with tagged command queuing enabled:
248
249 - IBM S12 0662
250 - Conner 1080S
251 - Quantum Atlas I
252 - Quantum Atlas II
253
254 If your controller has NVRAM, you can configure this feature per target
255 from the user setup tool. The Tekram Setup program allows to tune the
256 maximum number of queued commands up to 32. The Symbios Setup only allows
257 to enable or disable this feature.
258
259 The maximum number of simultaneous tagged commands queued to a device
260 is currently set to 8 by default. This value is suitable for most SCSI
261 disks. With large SCSI disks (>= 2GB, cache >= 512KB, average seek time
262 <= 10 ms), using a larger value may give better performances.
263
264 The sym53c8xx driver supports up to 255 commands per device, and the
265 generic ncr53c8xx driver supports up to 64, but using more than 32 is
266 generally not worth-while, unless you are using a very large disk or disk
267 array. It is noticeable that most of recent hard disks seem not to accept
268 more than 64 simultaneous commands. So, using more than 64 queued commands
269 is probably just resource wasting.
270
271 If your controller does not have NVRAM or if it is managed by the SDMS
272 BIOS/SETUP, you can configure tagged queueing feature and device queue
273 depths from the boot command-line. For example:
274
275 ncr53c8xx=tags:4/t2t3q15-t4q7/t1u0q32
276
277 will set tagged commands queue depths as follow:
278
279 - target 2 all luns on controller 0 --> 15
280 - target 3 all luns on controller 0 --> 15
281 - target 4 all luns on controller 0 --> 7
282 - target 1 lun 0 on controller 1 --> 32
283 - all other target/lun --> 4
284
285 In some special conditions, some SCSI disk firmwares may return a
286 QUEUE FULL status for a SCSI command. This behaviour is managed by the
287 driver using the following heuristic:
288
289 - Each time a QUEUE FULL status is returned, tagged queue depth is reduced
290 to the actual number of disconnected commands.
291
292 - Every 1000 successfully completed SCSI commands, if allowed by the
293 current limit, the maximum number of queueable commands is incremented.
294
295 Since QUEUE FULL status reception and handling is resource wasting, the
296 driver notifies by default this problem to user by indicating the actual
297 number of commands used and their status, as well as its decision on the
298 device queue depth change.
299 The heuristic used by the driver in handling QUEUE FULL ensures that the
300 impact on performances is not too bad. You can get rid of the messages by
301 setting verbose level to zero, as follow:
302
303 1st method: boot your system using 'ncr53c8xx=verb:0' option.
304 2nd method: apply "setverbose 0" control command to the proc fs entry
305 corresponding to your controller after boot-up.
306
307 6. Parity checking
308
309 The driver supports SCSI parity checking and PCI bus master parity
310 checking. These features must be enabled in order to ensure safe data
311 transfers. However, some flawed devices or mother boards will have
312 problems with parity. You can disable either PCI parity or SCSI parity
313 checking by entering appropriate options from the boot command line.
314 (See 10: Boot setup commands).
315
316 7. Profiling information
317
318 Profiling information is available through the proc SCSI file system.
319 Since gathering profiling information may impact performances, this
320 feature is disabled by default and requires a compilation configuration
321 option to be set to Y.
322
323 The device associated with a host has the following pathname:
324
325 /proc/scsi/ncr53c8xx/N (N=0,1,2 ....)
326
327 Generally, only 1 board is used on hardware configuration, and that device is:
328 /proc/scsi/ncr53c8xx/0
329
330 However, if the driver has been made as module, the number of the
331 hosts is incremented each time the driver is loaded.
332
333 In order to display profiling information, just enter:
334
335 cat /proc/scsi/ncr53c8xx/0
336
337 and you will get something like the following text:
338
339 -------------------------------------------------------
340 General information:
341 Chip NCR53C810, device id 0x1, revision id 0x2
342 IO port address 0x6000, IRQ number 10
343 Using memory mapped IO at virtual address 0x282c000
344 Synchronous transfer period 25, max commands per lun 4
345 Profiling information:
346 num_trans = 18014
347 num_kbytes = 671314
348 num_disc = 25763
349 num_break = 1673
350 num_int = 1685
351 num_fly = 18038
352 ms_setup = 4940
353 ms_data = 369940
354 ms_disc = 183090
355 ms_post = 1320
356 -------------------------------------------------------
357
358 General information is easy to understand. The device ID and the
359 revision ID identify the SCSI chip as follows:
360
361 Chip Device id Revision Id
362 ---- --------- -----------
363 810 0x1 < 0x10
364 810A 0x1 >= 0x10
365 815 0x4
366 825 0x3 < 0x10
367 860 0x6
368 825A 0x3 >= 0x10
369 875 0xf
370 895 0xc
371
372 The profiling information is updated upon completion of SCSI commands.
373 A data structure is allocated and zeroed when the host adapter is
374 attached. So, if the driver is a module, the profile counters are
375 cleared each time the driver is loaded. The "clearprof" command
376 allows you to clear these counters at any time.
377
378 The following counters are available:
379
380 ("num" prefix means "number of",
381 "ms" means milli-seconds)
382
383 num_trans
384 Number of completed commands
385 Example above: 18014 completed commands
386
387 num_kbytes
388 Number of kbytes transferred
389 Example above: 671 MB transferred
390
391 num_disc
392 Number of SCSI disconnections
393 Example above: 25763 SCSI disconnections
394
395 num_break
396 number of script interruptions (phase mismatch)
397 Example above: 1673 script interruptions
398
399 num_int
400 Number of interrupts other than "on the fly"
401 Example above: 1685 interruptions not "on the fly"
402
403 num_fly
404 Number of interrupts "on the fly"
405 Example above: 18038 interruptions "on the fly"
406
407 ms_setup
408 Elapsed time for SCSI commands setups
409 Example above: 4.94 seconds
410
411 ms_data
412 Elapsed time for data transfers
413 Example above: 369.94 seconds spent for data transfer
414
415 ms_disc
416 Elapsed time for SCSI disconnections
417 Example above: 183.09 seconds spent disconnected
418
419 ms_post
420 Elapsed time for command post processing
421 (time from SCSI status get to command completion call)
422 Example above: 1.32 seconds spent for post processing
423
424 Due to the 1/100 second tick of the system clock, "ms_post" time may
425 be wrong.
426
427 In the example above, we got 18038 interrupts "on the fly" and only
428 1673 script breaks generally due to disconnections inside a segment
429 of the scatter list.
430
431
432 8. Control commands
433
434 Control commands can be sent to the driver with write operations to
435 the proc SCSI file system. The generic command syntax is the
436 following:
437
438 echo "<verb> <parameters>" >/proc/scsi/ncr53c8xx/0
439 (assumes controller number is 0)
440
441 Using "all" for "<target>" parameter with the commands below will
442 apply to all targets of the SCSI chain (except the controller).
443
444 Available commands:
445
446 8.1 Set minimum synchronous period factor
447
448 setsync <target> <period factor>
449
450 target: target number
451 period: minimum synchronous period.
452 Maximum speed = 1000/(4*period factor) except for special
453 cases below.
454
455 Specify a period of 255, to force asynchronous transfer mode.
456
457 10 means 25 nano-seconds synchronous period
458 11 means 30 nano-seconds synchronous period
459 12 means 50 nano-seconds synchronous period
460
461 8.2 Set wide size
462
463 setwide <target> <size>
464
465 target: target number
466 size: 0=8 bits, 1=16bits
467
468 8.3 Set maximum number of concurrent tagged commands
469
470 settags <target> <tags>
471
472 target: target number
473 tags: number of concurrent tagged commands
474 must not be greater than SCSI_NCR_MAX_TAGS (default: 8)
475
476 8.4 Set order type for tagged command
477
478 setorder <order>
479
480 order: 3 possible values:
481 simple: use SIMPLE TAG for all operations (read and write)
482 ordered: use ORDERED TAG for all operations
483 default: use default tag type,
484 SIMPLE TAG for read operations
485 ORDERED TAG for write operations
486
487
488 8.5 Set debug mode
489
490 setdebug <list of debug flags>
491
492 Available debug flags:
493 alloc: print info about memory allocations (ccb, lcb)
494 queue: print info about insertions into the command start queue
495 result: print sense data on CHECK CONDITION status
496 scatter: print info about the scatter process
497 scripts: print info about the script binding process
498 tiny: print minimal debugging information
499 timing: print timing information of the NCR chip
500 nego: print information about SCSI negotiations
501 phase: print information on script interruptions
502
503 Use "setdebug" with no argument to reset debug flags.
504
505
506 8.6 Clear profile counters
507
508 clearprof
509
510 The profile counters are automatically cleared when the amount of
511 data transferred reaches 1000 GB in order to avoid overflow.
512 The "clearprof" command allows you to clear these counters at any time.
513
514
515 8.7 Set flag (no_disc)
516
517 setflag <target> <flag>
518
519 target: target number
520
521 For the moment, only one flag is available:
522
523 no_disc: not allow target to disconnect.
524
525 Do not specify any flag in order to reset the flag. For example:
526 - setflag 4
527 will reset no_disc flag for target 4, so will allow it disconnections.
528 - setflag all
529 will allow disconnection for all devices on the SCSI bus.
530
531
532 8.8 Set verbose level
533
534 setverbose #level
535
536 The driver default verbose level is 1. This command allows to change
537 th driver verbose level after boot-up.
538
539 8.9 Reset all logical units of a target
540
541 resetdev <target>
542
543 target: target number
544 The driver will try to send a BUS DEVICE RESET message to the target.
545 (Only supported by the SYM53C8XX driver and provided for test purpose)
546
547 8.10 Abort all tasks of all logical units of a target
548
549 cleardev <target>
550
551 target: target number
552 The driver will try to send a ABORT message to all the logical units
553 of the target.
554 (Only supported by the SYM53C8XX driver and provided for test purpose)
555
556
557 9. Configuration parameters
558
559 If the firmware of all your devices is perfect enough, all the
560 features supported by the driver can be enabled at start-up. However,
561 if only one has a flaw for some SCSI feature, you can disable the
562 support by the driver of this feature at linux start-up and enable
563 this feature after boot-up only for devices that support it safely.
564
565 CONFIG_SCSI_NCR53C8XX_IOMAPPED (default answer: n)
566 Answer "y" if you suspect your mother board to not allow memory mapped I/O.
567 May slow down performance a little. This option is required by
568 Linux/PPC and is used no matter what you select here. Linux/PPC
569 suffers no performance loss with this option since all IO is memory
570 mapped anyway.
571
572 CONFIG_SCSI_NCR53C8XX_DEFAULT_TAGS (default answer: 8)
573 Default tagged command queue depth.
574
575 CONFIG_SCSI_NCR53C8XX_MAX_TAGS (default answer: 8)
576 This option allows you to specify the maximum number of tagged commands
577 that can be queued to a device. The maximum supported value is 32.
578
579 CONFIG_SCSI_NCR53C8XX_SYNC (default answer: 5)
580 This option allows you to specify the frequency in MHz the driver
581 will use at boot time for synchronous data transfer negotiations.
582 This frequency can be changed later with the "setsync" control command.
583 0 means "asynchronous data transfers".
584
585 CONFIG_SCSI_NCR53C8XX_FORCE_SYNC_NEGO (default answer: n)
586 Force synchronous negotiation for all SCSI-2 devices.
587 Some SCSI-2 devices do not report this feature in byte 7 of inquiry
588 response but do support it properly (TAMARACK scanners for example).
589
590 CONFIG_SCSI_NCR53C8XX_NO_DISCONNECT (default and only reasonable answer: n)
591 If you suspect a device of yours does not properly support disconnections,
592 you can answer "y". Then, all SCSI devices will never disconnect the bus
593 even while performing long SCSI operations.
594
595 CONFIG_SCSI_NCR53C8XX_SYMBIOS_COMPAT
596 Genuine SYMBIOS boards use GPIO0 in output for controller LED and GPIO3
597 bit as a flag indicating singled-ended/differential interface.
598 If all the boards of your system are genuine SYMBIOS boards or use
599 BIOS and drivers from SYMBIOS, you would want to enable this option.
600 This option must NOT be enabled if your system has at least one 53C8XX
601 based scsi board with a vendor-specific BIOS.
602 For example, Tekram DC-390/U, DC-390/W and DC-390/F scsi controllers
603 use a vendor-specific BIOS and are known to not use SYMBIOS compatible
604 GPIO wiring. So, this option must not be enabled if your system has
605 such a board installed.
606
607 CONFIG_SCSI_NCR53C8XX_NVRAM_DETECT
608 Enable support for reading the serial NVRAM data on Symbios and
609 some Symbios compatible cards, and Tekram DC390W/U/F cards. Useful for
610 systems with more than one Symbios compatible controller where at least
611 one has a serial NVRAM, or for a system with a mixture of Symbios and
612 Tekram cards. Enables setting the boot order of host adaptors
613 to something other than the default order or "reverse probe" order.
614 Also enables Symbios and Tekram cards to be distinguished so
615 CONFIG_SCSI_NCR53C8XX_SYMBIOS_COMPAT may be set in a system with a
616 mixture of Symbios and Tekram cards so the Symbios cards can make use of
617 the full range of Symbios features, differential, led pin, without
618 causing problems for the Tekram card(s).
619
620 10. Boot setup commands
621
622 10.1 Syntax
623
624 Setup commands can be passed to the driver either at boot time or as a
625 string variable using 'insmod'.
626
627 A boot setup command for the ncr53c8xx (sym53c8xx) driver begins with the
628 driver name "ncr53c8xx="(sym53c8xx). The kernel syntax parser then expects
629 an optional list of integers separated with comma followed by an optional
630 list of comma-separated strings. Example of boot setup command under lilo
631 prompt:
632
633 lilo: linux root=/dev/hda2 ncr53c8xx=tags:4,sync:10,debug:0x200
634
635 - enable tagged commands, up to 4 tagged commands queued.
636 - set synchronous negotiation speed to 10 Mega-transfers / second.
637 - set DEBUG_NEGO flag.
638
639 Since comma seems not to be allowed when defining a string variable using
640 'insmod', the driver also accepts <space> as option separator.
641 The following command will install driver module with the same options as
642 above.
643
644 insmod ncr53c8xx.o ncr53c8xx="tags:4 sync:10 debug:0x200"
645
646 For the moment, the integer list of arguments is discarded by the driver.
647 It will be used in the future in order to allow a per controller setup.
648
649 Each string argument must be specified as "keyword:value". Only lower-case
650 characters and digits are allowed.
651
652 In a system that contains multiple 53C8xx adapters insmod will install the
653 specified driver on each adapter. To exclude a chip use the 'excl' keyword.
654
655 The sequence of commands,
656
657 insmod sym53c8xx sym53c8xx=excl:0x1400
658 insmod ncr53c8xx
659
660 installs the sym53c8xx driver on all adapters except the one at IO port
661 address 0x1400 and then installs the ncr53c8xx driver to the adapter at IO
662 port address 0x1400.
663
664
665 10.2 Available arguments
666
667 10.2.1 Master parity checking
668 mpar:y enabled
669 mpar:n disabled
670
671 10.2.2 Scsi parity checking
672 spar:y enabled
673 spar:n disabled
674
675 10.2.3 Scsi disconnections
676 disc:y enabled
677 disc:n disabled
678
679 10.2.4 Special features
680 Only apply to 810A, 825A, 860, 875 and 895 controllers.
681 Have no effect with other ones.
682 specf:y (or 1) enabled
683 specf:n (or 0) disabled
684 specf:3 enabled except Memory Write And Invalidate
685 The default driver setup is 'specf:3'. As a consequence, option 'specf:y'
686 must be specified in the boot setup command to enable Memory Write And
687 Invalidate.
688
689 10.2.5 Ultra SCSI support
690 Only apply to 860, 875, 895, 895a, 896, 1010 and 1010_66 controllers.
691 Have no effect with other ones.
692 ultra:n All ultra speeds enabled
693 ultra:2 Ultra2 enabled
694 ultra:1 Ultra enabled
695 ultra:0 Ultra speeds disabled
696
697 10.2.6 Default number of tagged commands
698 tags:0 (or tags:1 ) tagged command queuing disabled
699 tags:#tags (#tags > 1) tagged command queuing enabled
700 #tags will be truncated to the max queued commands configuration parameter.
701 This option also allows to specify a command queue depth for each device
702 that support tagged command queueing.
703 Example:
704 ncr53c8xx=tags:10/t2t3q16-t5q24/t1u2q32
705 will set devices queue depth as follow:
706 - controller #0 target #2 and target #3 -> 16 commands,
707 - controller #0 target #5 -> 24 commands,
708 - controller #1 target #1 logical unit #2 -> 32 commands,
709 - all other logical units (all targets, all controllers) -> 10 commands.
710
711 10.2.7 Default synchronous period factor
712 sync:255 disabled (asynchronous transfer mode)
713 sync:#factor
714 #factor = 10 Ultra-2 SCSI 40 Mega-transfers / second
715 #factor = 11 Ultra-2 SCSI 33 Mega-transfers / second
716 #factor < 25 Ultra SCSI 20 Mega-transfers / second
717 #factor < 50 Fast SCSI-2
718
719 In all cases, the driver will use the minimum transfer period supported by
720 controllers according to NCR53C8XX chip type.
721
722 10.2.8 Negotiate synchronous with all devices
723 (force sync nego)
724 fsn:y enabled
725 fsn:n disabled
726
727 10.2.9 Verbosity level
728 verb:0 minimal
729 verb:1 normal
730 verb:2 too much
731
732 10.2.10 Debug mode
733 debug:0 clear debug flags
734 debug:#x set debug flags
735 #x is an integer value combining the following power-of-2 values:
736 DEBUG_ALLOC 0x1
737 DEBUG_PHASE 0x2
738 DEBUG_POLL 0x4
739 DEBUG_QUEUE 0x8
740 DEBUG_RESULT 0x10
741 DEBUG_SCATTER 0x20
742 DEBUG_SCRIPT 0x40
743 DEBUG_TINY 0x80
744 DEBUG_TIMING 0x100
745 DEBUG_NEGO 0x200
746 DEBUG_TAGS 0x400
747 DEBUG_FREEZE 0x800
748 DEBUG_RESTART 0x1000
749
750 You can play safely with DEBUG_NEGO. However, some of these flags may
751 generate bunches of syslog messages.
752
753 10.2.11 Burst max
754 burst:0 burst disabled
755 burst:255 get burst length from initial IO register settings.
756 burst:#x burst enabled (1<<#x burst transfers max)
757 #x is an integer value which is log base 2 of the burst transfers max.
758 The NCR53C875 and NCR53C825A support up to 128 burst transfers (#x = 7).
759 Other chips only support up to 16 (#x = 4).
760 This is a maximum value. The driver set the burst length according to chip
761 and revision ids. By default the driver uses the maximum value supported
762 by the chip.
763
764 10.2.12 LED support
765 led:1 enable LED support
766 led:0 disable LED support
767 Donnot enable LED support if your scsi board does not use SDMS BIOS.
768 (See 'Configuration parameters')
769
770 10.2.13 Max wide
771 wide:1 wide scsi enabled
772 wide:0 wide scsi disabled
773 Some scsi boards use a 875 (ultra wide) and only supply narrow connectors.
774 If you have connected a wide device with a 50 pins to 68 pins cable
775 converter, any accepted wide negotiation will break further data transfers.
776 In such a case, using "wide:0" in the bootup command will be helpful.
777
778 10.2.14 Differential mode
779 diff:0 never set up diff mode
780 diff:1 set up diff mode if BIOS set it
781 diff:2 always set up diff mode
782 diff:3 set diff mode if GPIO3 is not set
783
784 10.2.15 IRQ mode
785 irqm:0 always open drain
786 irqm:1 same as initial settings (assumed BIOS settings)
787 irqm:2 always totem pole
788 irqm:0x10 driver will not use IRQF_SHARED flag when requesting irq
789
790 (Bits 0x10 and 0x20 can be combined with hardware irq mode option)
791
792 10.2.16 Reverse probe
793 revprob:n probe chip ids from the PCI configuration in this order:
794 810, 815, 820, 860, 875, 885, 895, 896
795 revprob:y probe chip ids in the reverse order.
796
797 10.2.17 Fix up PCI configuration space
798 pcifix:<option bits>
799
800 Available option bits:
801 0x0: No attempt to fix PCI configuration space registers values.
802 0x1: Set PCI cache-line size register if not set.
803 0x2: Set write and invalidate bit in PCI command register.
804 0x4: Increase if necessary PCI latency timer according to burst max.
805
806 Use 'pcifix:7' in order to allow the driver to fix up all PCI features.
807
808 10.2.18 Serial NVRAM
809 nvram:n do not look for serial NVRAM
810 nvram:y test controllers for onboard serial NVRAM
811 (alternate binary form)
812 mvram=<bits options>
813 0x01 look for NVRAM (equivalent to nvram=y)
814 0x02 ignore NVRAM "Synchronous negotiation" parameters for all devices
815 0x04 ignore NVRAM "Wide negotiation" parameter for all devices
816 0x08 ignore NVRAM "Scan at boot time" parameter for all devices
817 0x80 also attach controllers set to OFF in the NVRAM (sym53c8xx only)
818
819 10.2.19 Check SCSI BUS
820 buschk:<option bits>
821
822 Available option bits:
823 0x0: No check.
824 0x1: Check and do not attach the controller on error.
825 0x2: Check and just warn on error.
826 0x4: Disable SCSI bus integrity checking.
827
828 10.2.20 Exclude a host from being attached
829 excl=<io_address>
830
831 Prevent host at a given io address from being attached.
832 For example 'ncr53c8xx=excl:0xb400,excl:0xc000' indicate to the
833 ncr53c8xx driver not to attach hosts at address 0xb400 and 0xc000.
834
835 10.2.21 Suggest a default SCSI id for hosts
836 hostid:255 no id suggested.
837 hostid:#x (0 < x < 7) x suggested for hosts SCSI id.
838
839 If a host SCSI id is available from the NVRAM, the driver will ignore
840 any value suggested as boot option. Otherwise, if a suggested value
841 different from 255 has been supplied, it will use it. Otherwise, it will
842 try to deduce the value previously set in the hardware and use value
843 7 if the hardware value is zero.
844
845 10.2.22 Enable use of IMMEDIATE ARBITRATION
846 (only supported by the sym53c8xx driver. See 10.7 for more details)
847 iarb:0 do not use this feature.
848 iarb:#x use this feature according to bit fields as follow:
849
850 bit 0 (1) : enable IARB each time the initiator has been reselected
851 when it arbitrated for the SCSI BUS.
852 (#x >> 4) : maximum number of successive settings of IARB if the initiator
853 win arbitration and it has other commands to send to a device.
854
855 Boot fail safe
856 safe:y load the following assumed fail safe initial setup
857
858 master parity disabled mpar:n
859 scsi parity enabled spar:y
860 disconnections not allowed disc:n
861 special features disabled specf:n
862 ultra scsi disabled ultra:n
863 force sync negotiation disabled fsn:n
864 reverse probe disabled revprob:n
865 PCI fix up disabled pcifix:0
866 serial NVRAM enabled nvram:y
867 verbosity level 2 verb:2
868 tagged command queuing disabled tags:0
869 synchronous negotiation disabled sync:255
870 debug flags none debug:0
871 burst length from BIOS settings burst:255
872 LED support disabled led:0
873 wide support disabled wide:0
874 settle time 10 seconds settle:10
875 differential support from BIOS settings diff:1
876 irq mode from BIOS settings irqm:1
877 SCSI BUS check do not attach on error buschk:1
878 immediate arbitration disabled iarb:0
879
880 10.3 Advised boot setup commands
881
882 If the driver has been configured with default options, the equivalent
883 boot setup is:
884
885 ncr53c8xx=mpar:y,spar:y,disc:y,specf:3,fsn:n,ultra:2,fsn:n,revprob:n,verb:1\
886 tags:0,sync:50,debug:0,burst:7,led:0,wide:1,settle:2,diff:0,irqm:0
887
888 For an installation diskette or a safe but not fast system,
889 boot setup can be:
890
891 ncr53c8xx=safe:y,mpar:y,disc:y
892 ncr53c8xx=safe:y,disc:y
893 ncr53c8xx=safe:y,mpar:y
894 ncr53c8xx=safe:y
895
896 My personal system works flawlessly with the following equivalent setup:
897
898 ncr53c8xx=mpar:y,spar:y,disc:y,specf:1,fsn:n,ultra:2,fsn:n,revprob:n,verb:1\
899 tags:32,sync:12,debug:0,burst:7,led:1,wide:1,settle:2,diff:0,irqm:0
900
901 The driver prints its actual setup when verbosity level is 2. You can try
902 "ncr53c8xx=verb:2" to get the "static" setup of the driver, or add "verb:2"
903 to your boot setup command in order to check the actual setup the driver is
904 using.
905
906 10.4 PCI configuration fix-up boot option
907
908 pcifix:<option bits>
909
910 Available option bits:
911 0x1: Set PCI cache-line size register if not set.
912 0x2: Set write and invalidate bit in PCI command register.
913
914 Use 'pcifix:3' in order to allow the driver to fix both PCI features.
915
916 These options only apply to new SYMBIOS chips 810A, 825A, 860, 875
917 and 895 and are only supported for Pentium and 486 class processors.
918 Recent SYMBIOS 53C8XX scsi processors are able to use PCI read multiple
919 and PCI write and invalidate commands. These features require the
920 cache line size register to be properly set in the PCI configuration
921 space of the chips. On the other hand, chips will use PCI write and
922 invalidate commands only if the corresponding bit is set to 1 in the
923 PCI command register.
924
925 Not all PCI bioses set the PCI cache line register and the PCI write and
926 invalidate bit in the PCI configuration space of 53C8XX chips.
927 Optimized PCI accesses may be broken for some PCI/memory controllers or
928 make problems with some PCI boards.
929
930 This fix-up worked flawlessly on my previous system.
931 (MB Triton HX / 53C875 / 53C810A)
932 I use these options at my own risks as you will do if you decide to
933 use them too.
934
935
936 10.5 Serial NVRAM support boot option
937
938 nvram:n do not look for serial NVRAM
939 nvram:y test controllers for onboard serial NVRAM
940
941 This option can also been entered as an hexadecimal value that allows
942 to control what information the driver will get from the NVRAM and what
943 information it will ignore.
944 For details see '17. Serial NVRAM support'.
945
946 When this option is enabled, the driver tries to detect all boards using
947 a Serial NVRAM. This memory is used to hold user set up parameters.
948
949 The parameters the driver is able to get from the NVRAM depend on the
950 data format used, as follow:
951
952 Tekram format Symbios format
953 General and host parameters
954 Boot order N Y
955 Host SCSI ID Y Y
956 SCSI parity checking Y Y
957 Verbose boot messages N Y
958 SCSI devices parameters
959 Synchronous transfer speed Y Y
960 Wide 16 / Narrow Y Y
961 Tagged Command Queuing enabled Y Y
962 Disconnections enabled Y Y
963 Scan at boot time N Y
964
965 In order to speed up the system boot, for each device configured without
966 the "scan at boot time" option, the driver forces an error on the
967 first TEST UNIT READY command received for this device.
968
969 Some SDMS BIOS revisions seem to be unable to boot cleanly with very fast
970 hard disks. In such a situation you cannot configure the NVRAM with
971 optimized parameters value.
972
973 The 'nvram' boot option can be entered in hexadecimal form in order
974 to ignore some options configured in the NVRAM, as follow:
975
976 mvram=<bits options>
977 0x01 look for NVRAM (equivalent to nvram=y)
978 0x02 ignore NVRAM "Synchronous negotiation" parameters for all devices
979 0x04 ignore NVRAM "Wide negotiation" parameter for all devices
980 0x08 ignore NVRAM "Scan at boot time" parameter for all devices
981 0x80 also attach controllers set to OFF in the NVRAM (sym53c8xx only)
982
983 Option 0x80 is only supported by the sym53c8xx driver and is disabled by
984 default. Result is that, by default (option not set), the sym53c8xx driver
985 will not attach controllers set to OFF in the NVRAM.
986
987 The ncr53c8xx always tries to attach all the controllers. Option 0x80 has
988 not been added to the ncr53c8xx driver, since it has been reported to
989 confuse users who use this driver since a long time. If you desire a
990 controller not to be attached by the ncr53c8xx driver at Linux boot, you
991 must use the 'excl' driver boot option.
992
993 10.6 SCSI BUS checking boot option.
994
995 When this option is set to a non-zero value, the driver checks SCSI lines
996 logic state, 100 micro-seconds after having asserted the SCSI RESET line.
997 The driver just reads SCSI lines and checks all lines read FALSE except RESET.
998 Since SCSI devices shall release the BUS at most 800 nano-seconds after SCSI
999 RESET has been asserted, any signal to TRUE may indicate a SCSI BUS problem.
1000 Unfortunately, the following common SCSI BUS problems are not detected:
1001 - Only 1 terminator installed.
1002 - Misplaced terminators.
1003 - Bad quality terminators.
1004 On the other hand, either bad cabling, broken devices, not conformant
1005 devices, ... may cause a SCSI signal to be wrong when te driver reads it.
1006
1007 10.7 IMMEDIATE ARBITRATION boot option
1008
1009 This option is only supported by the SYM53C8XX driver (not by the NCR53C8XX).
1010
1011 SYMBIOS 53C8XX chips are able to arbitrate for the SCSI BUS as soon as they
1012 have detected an expected disconnection (BUS FREE PHASE). For this process
1013 to be started, bit 1 of SCNTL1 IO register must be set when the chip is
1014 connected to the SCSI BUS.
1015
1016 When this feature has been enabled for the current connection, the chip has
1017 every chance to win arbitration if only devices with lower priority are
1018 competing for the SCSI BUS. By the way, when the chip is using SCSI id 7,
1019 then it will for sure win the next SCSI BUS arbitration.
1020
1021 Since, there is no way to know what devices are trying to arbitrate for the
1022 BUS, using this feature can be extremely unfair. So, you are not advised
1023 to enable it, or at most enable this feature for the case the chip lost
1024 the previous arbitration (boot option 'iarb:1').
1025
1026 This feature has the following advantages:
1027
1028 a) Allow the initiator with ID 7 to win arbitration when it wants so.
1029 b) Overlap at least 4 micro-seconds of arbitration time with the execution
1030 of SCRIPTS that deal with the end of the current connection and that
1031 starts the next job.
1032
1033 Hmmm... But (a) may just prevent other devices from reselecting the initiator,
1034 and delay data transfers or status/completions, and (b) may just waste
1035 SCSI BUS bandwidth if the SCRIPTS execution lasts more than 4 micro-seconds.
1036
1037 The use of IARB needs the SCSI_NCR_IARB_SUPPORT option to have been defined
1038 at compile time and the 'iarb' boot option to have been set to a non zero
1039 value at boot time. It is not that useful for real work, but can be used
1040 to stress SCSI devices or for some applications that can gain advantage of
1041 it. By the way, if you experience badnesses like 'unexpected disconnections',
1042 'bad reselections', etc... when using IARB on heavy IO load, you should not
1043 be surprised, because force-feeding anything and blocking its arse at the
1044 same time cannot work for a long time. :-))
1045
1046
1047 11. Some constants and flags of the ncr53c8xx.h header file
1048
1049 Some of these are defined from the configuration parameters. To
1050 change other "defines", you must edit the header file. Do that only
1051 if you know what you are doing.
1052
1053 SCSI_NCR_SETUP_SPECIAL_FEATURES (default: defined)
1054 If defined, the driver will enable some special features according
1055 to chip and revision id.
1056 For 810A, 860, 825A, 875 and 895 scsi chips, this option enables
1057 support of features that reduce load of PCI bus and memory accesses
1058 during scsi transfer processing: burst op-code fetch, read multiple,
1059 read line, prefetch, cache line, write and invalidate,
1060 burst 128 (875 only), large dma fifo (875 only), offset 16 (875 only).
1061 Can be changed by the following boot setup command:
1062 ncr53c8xx=specf:n
1063
1064 SCSI_NCR_IOMAPPED (default: not defined)
1065 If defined, normal I/O is forced.
1066
1067 SCSI_NCR_SHARE_IRQ (default: defined)
1068 If defined, request shared IRQ.
1069
1070 SCSI_NCR_MAX_TAGS (default: 8)
1071 Maximum number of simultaneous tagged commands to a device.
1072 Can be changed by "settags <target> <maxtags>"
1073
1074 SCSI_NCR_SETUP_DEFAULT_SYNC (default: 50)
1075 Transfer period factor the driver will use at boot time for synchronous
1076 negotiation. 0 means asynchronous.
1077 Can be changed by "setsync <target> <period factor>"
1078
1079 SCSI_NCR_SETUP_DEFAULT_TAGS (default: 8)
1080 Default number of simultaneous tagged commands to a device.
1081 < 1 means tagged command queuing disabled at start-up.
1082
1083 SCSI_NCR_ALWAYS_SIMPLE_TAG (default: defined)
1084 Use SIMPLE TAG for read and write commands.
1085 Can be changed by "setorder <ordered|simple|default>"
1086
1087 SCSI_NCR_SETUP_DISCONNECTION (default: defined)
1088 If defined, targets are allowed to disconnect.
1089
1090 SCSI_NCR_SETUP_FORCE_SYNC_NEGO (default: not defined)
1091 If defined, synchronous negotiation is tried for all SCSI-2 devices.
1092 Can be changed by "setsync <target> <period>"
1093
1094 SCSI_NCR_SETUP_MASTER_PARITY (default: defined)
1095 If defined, master parity checking is enabled.
1096
1097 SCSI_NCR_SETUP_SCSI_PARITY (default: defined)
1098 If defined, SCSI parity checking is enabled.
1099
1100 SCSI_NCR_PROFILE_SUPPORT (default: not defined)
1101 If defined, profiling information is gathered.
1102
1103 SCSI_NCR_MAX_SCATTER (default: 128)
1104 Scatter list size of the driver ccb.
1105
1106 SCSI_NCR_MAX_TARGET (default: 16)
1107 Max number of targets per host.
1108
1109 SCSI_NCR_MAX_HOST (default: 2)
1110 Max number of host controllers.
1111
1112 SCSI_NCR_SETTLE_TIME (default: 2)
1113 Number of seconds the driver will wait after reset.
1114
1115 SCSI_NCR_TIMEOUT_ALERT (default: 3)
1116 If a pending command will time out after this amount of seconds,
1117 an ordered tag is used for the next command.
1118 Avoids timeouts for unordered tagged commands.
1119
1120 SCSI_NCR_CAN_QUEUE (default: 7*SCSI_NCR_MAX_TAGS)
1121 Max number of commands that can be queued to a host.
1122
1123 SCSI_NCR_CMD_PER_LUN (default: SCSI_NCR_MAX_TAGS)
1124 Max number of commands queued to a host for a device.
1125
1126 SCSI_NCR_SG_TABLESIZE (default: SCSI_NCR_MAX_SCATTER-1)
1127 Max size of the Linux scatter/gather list.
1128
1129 SCSI_NCR_MAX_LUN (default: 8)
1130 Max number of LUNs per target.
1131
1132
1133 12. Installation
1134
1135 This driver is part of the linux kernel distribution.
1136 Driver files are located in the sub-directory "drivers/scsi" of the
1137 kernel source tree.
1138
1139 Driver files:
1140
1141 README.ncr53c8xx : this file
1142 ChangeLog.ncr53c8xx : change log
1143 ncr53c8xx.h : definitions
1144 ncr53c8xx.c : the driver code
1145
1146 New driver versions are made available separately in order to allow testing
1147 changes and new features prior to including them into the linux kernel
1148 distribution. The following URL provides information on latest available
1149 patches:
1150
1151 ftp://ftp.tux.org/pub/people/gerard-roudier/README
1152
1153
1154 13. Architecture dependent features.
1155
1156 <Not yet written>
1157
1158
1159 14. Known problems
1160
1161 14.1 Tagged commands with Iomega Jaz device
1162
1163 I have not tried this device, however it has been reported to me the
1164 following: This device is capable of Tagged command queuing. However
1165 while spinning up, it rejects Tagged commands. This behaviour is
1166 conforms to 6.8.2 of SCSI-2 specifications. The current behaviour of
1167 the driver in that situation is not satisfying. So do not enable
1168 Tagged command queuing for devices that are able to spin down. The
1169 other problem that may appear is timeouts. The only way to avoid
1170 timeouts seems to edit linux/drivers/scsi/sd.c and to increase the
1171 current timeout values.
1172
1173 14.2 Device names change when another controller is added.
1174
1175 When you add a new NCR53C8XX chip based controller to a system that already
1176 has one or more controllers of this family, it may happen that the order
1177 the driver registers them to the kernel causes problems due to device
1178 name changes.
1179 When at least one controller uses NvRAM, SDMS BIOS version 4 allows you to
1180 define the order the BIOS will scan the scsi boards. The driver attaches
1181 controllers according to BIOS information if NvRAM detect option is set.
1182
1183 If your controllers do not have NvRAM, you can:
1184
1185 - Ask the driver to probe chip ids in reverse order from the boot command
1186 line: ncr53c8xx=revprob:y
1187 - Make appropriate changes in the fstab.
1188 - Use the 'scsidev' tool from Eric Youngdale.
1189
1190 14.3 Using only 8 bit devices with a WIDE SCSI controller.
1191
1192 When only 8 bit NARROW devices are connected to a 16 bit WIDE SCSI controller,
1193 you must ensure that lines of the wide part of the SCSI BUS are pulled-up.
1194 This can be achieved by ENABLING the WIDE TERMINATOR portion of the SCSI
1195 controller card.
1196 The TYAN 1365 documentation revision 1.2 is not correct about such settings.
1197 (page 10, figure 3.3).
1198
1199 14.4 Possible data corruption during a Memory Write and Invalidate
1200
1201 This problem is described in SYMBIOS DEL 397, Part Number 69-039241, ITEM 4.
1202
1203 In some complex situations, 53C875 chips revision <= 3 may start a PCI
1204 Write and Invalidate Command at a not cache-line-aligned 4 DWORDS boundary.
1205 This is only possible when Cache Line Size is 8 DWORDS or greater.
1206 Pentium systems use a 8 DWORDS cache line size and so are concerned by
1207 this chip bug, unlike i486 systems that use a 4 DWORDS cache line size.
1208
1209 When this situation occurs, the chip may complete the Write and Invalidate
1210 command after having only filled part of the last cache line involved in
1211 the transfer, leaving to data corruption the remainder of this cache line.
1212
1213 Not using Write And Invalidate obviously gets rid of this chip bug, and so
1214 it is now the default setting of the driver.
1215 However, for people like me who want to enable this feature, I have added
1216 part of a work-around suggested by SYMBIOS. This work-around resets the
1217 addressing logic when the DATA IN phase is entered and so prevents the bug
1218 from being triggered for the first SCSI MOVE of the phase. This work-around
1219 should be enough according to the following:
1220
1221 The only driver internal data structure that is greater than 8 DWORDS and
1222 that is moved by the SCRIPTS processor is the 'CCB header' that contains
1223 the context of the SCSI transfer. This data structure is aligned on 8 DWORDS
1224 boundary (Pentium Cache Line Size), and so is immune to this chip bug, at
1225 least on Pentium systems.
1226 But the conditions of this bug can be met when a SCSI read command is
1227 performed using a buffer that is 4 DWORDS but not cache-line aligned.
1228 This cannot happen under Linux when scatter/gather lists are used since
1229 they only refer to system buffers that are well aligned. So, a work around
1230 may only be needed under Linux when a scatter/gather list is not used and
1231 when the SCSI DATA IN phase is reentered after a phase mismatch.
1232
1233 15. SCSI problem troubleshooting
1234
1235 15.1 Problem tracking
1236
1237 Most SCSI problems are due to a non conformant SCSI bus or to buggy
1238 devices. If unfortunately you have SCSI problems, you can check the
1239 following things:
1240
1241 - SCSI bus cables
1242 - terminations at both end of the SCSI chain
1243 - linux syslog messages (some of them may help you)
1244
1245 If you do not find the source of problems, you can configure the
1246 driver with no features enabled.
1247
1248 - only asynchronous data transfers
1249 - tagged commands disabled
1250 - disconnections not allowed
1251
1252 Now, if your SCSI bus is ok, your system have every chance to work
1253 with this safe configuration but performances will not be optimal.
1254
1255 If it still fails, then you can send your problem description to
1256 appropriate mailing lists or news-groups. Send me a copy in order to
1257 be sure I will receive it. Obviously, a bug in the driver code is
1258 possible.
1259
1260 My email address: Gerard Roudier <groudier@free.fr>
1261
1262 Allowing disconnections is important if you use several devices on
1263 your SCSI bus but often causes problems with buggy devices.
1264 Synchronous data transfers increases throughput of fast devices like
1265 hard disks. Good SCSI hard disks with a large cache gain advantage of
1266 tagged commands queuing.
1267
1268 Try to enable one feature at a time with control commands. For example:
1269
1270 - echo "setsync all 25" >/proc/scsi/ncr53c8xx/0
1271 Will enable fast synchronous data transfer negotiation for all targets.
1272
1273 - echo "setflag 3" >/proc/scsi/ncr53c8xx/0
1274 Will reset flags (no_disc) for target 3, and so will allow it to disconnect
1275 the SCSI Bus.
1276
1277 - echo "settags 3 8" >/proc/scsi/ncr53c8xx/0
1278 Will enable tagged command queuing for target 3 if that device supports it.
1279
1280 Once you have found the device and the feature that cause problems, just
1281 disable that feature for that device.
1282
1283 15.2 Understanding hardware error reports
1284
1285 When the driver detects an unexpected error condition, it may display a
1286 message of the following pattern.
1287
1288 sym53c876-0:1: ERROR (0:48) (1-21-65) (f/95) @ (script 7c0:19000000).
1289 sym53c876-0: script cmd = 19000000
1290 sym53c876-0: regdump: da 10 80 95 47 0f 01 07 75 01 81 21 80 01 09 00.
1291
1292 Some fields in such a message may help you understand the cause of the
1293 problem, as follows:
1294
1295 sym53c876-0:1: ERROR (0:48) (1-21-65) (f/95) @ (script 7c0:19000000).
1296 ............A.........B.C....D.E..F....G.H.......I.....J...K.......
1297
1298 Field A : target number.
1299 SCSI ID of the device the controller was talking with at the moment the
1300 error occurs.
1301
1302 Field B : DSTAT io register (DMA STATUS)
1303 Bit 0x40 : MDPE Master Data Parity Error
1304 Data parity error detected on the PCI BUS.
1305 Bit 0x20 : BF Bus Fault
1306 PCI bus fault condition detected
1307 Bit 0x01 : IID Illegal Instruction Detected
1308 Set by the chip when it detects an Illegal Instruction format
1309 on some condition that makes an instruction illegal.
1310 Bit 0x80 : DFE Dma Fifo Empty
1311 Pure status bit that does not indicate an error.
1312 If the reported DSTAT value contains a combination of MDPE (0x40),
1313 BF (0x20), then the cause may be likely due to a PCI BUS problem.
1314
1315 Field C : SIST io register (SCSI Interrupt Status)
1316 Bit 0x08 : SGE SCSI GROSS ERROR
1317 Indicates that the chip detected a severe error condition
1318 on the SCSI BUS that prevents the SCSI protocol from functioning
1319 properly.
1320 Bit 0x04 : UDC Unexpected Disconnection
1321 Indicates that the device released the SCSI BUS when the chip
1322 was not expecting this to happen. A device may behave so to
1323 indicate the SCSI initiator that an error condition not reportable using the SCSI protocol has occurred.
1324 Bit 0x02 : RST SCSI BUS Reset
1325 Generally SCSI targets do not reset the SCSI BUS, although any
1326 device on the BUS can reset it at any time.
1327 Bit 0x01 : PAR Parity
1328 SCSI parity error detected.
1329 On a faulty SCSI BUS, any error condition among SGE (0x08), UDC (0x04) and
1330 PAR (0x01) may be detected by the chip. If your SCSI system sometimes
1331 encounters such error conditions, especially SCSI GROSS ERROR, then a SCSI
1332 BUS problem is likely the cause of these errors.
1333
1334 For fields D,E,F,G and H, you may look into the sym53c8xx_defs.h file
1335 that contains some minimal comments on IO register bits.
1336 Field D : SOCL Scsi Output Control Latch
1337 This register reflects the state of the SCSI control lines the
1338 chip want to drive or compare against.
1339 Field E : SBCL Scsi Bus Control Lines
1340 Actual value of control lines on the SCSI BUS.
1341 Field F : SBDL Scsi Bus Data Lines
1342 Actual value of data lines on the SCSI BUS.
1343 Field G : SXFER SCSI Transfer
1344 Contains the setting of the Synchronous Period for output and
1345 the current Synchronous offset (offset 0 means asynchronous).
1346 Field H : SCNTL3 Scsi Control Register 3
1347 Contains the setting of timing values for both asynchronous and
1348 synchronous data transfers.
1349
1350 Understanding Fields I, J, K and dumps requires to have good knowledge of
1351 SCSI standards, chip cores functionnals and internal driver data structures.
1352 You are not required to decode and understand them, unless you want to help
1353 maintain the driver code.
1354
1355 16. Synchronous transfer negotiation tables
1356
1357 Tables below have been created by calling the routine the driver uses
1358 for synchronisation negotiation timing calculation and chip setting.
1359 The first table corresponds to Ultra chips 53875 and 53C860 with 80 MHz
1360 clock and 5 clock divisors.
1361 The second one has been calculated by setting the scsi clock to 40 Mhz
1362 and using 4 clock divisors and so applies to all NCR53C8XX chips in fast
1363 SCSI-2 mode.
1364
1365 Periods are in nano-seconds and speeds are in Mega-transfers per second.
1366 1 Mega-transfers/second means 1 MB/s with 8 bits SCSI and 2 MB/s with
1367 Wide16 SCSI.
1368
1369 16.1 Synchronous timings for 53C895, 53C875 and 53C860 SCSI controllers
1370
1371 ----------------------------------------------
1372 Negotiated NCR settings
1373 Factor Period Speed Period Speed
1374 ------ ------ ------ ------ ------
1375 10 25 40.000 25 40.000 (53C895 only)
1376 11 30.2 33.112 31.25 32.000 (53C895 only)
1377 12 50 20.000 50 20.000
1378 13 52 19.230 62 16.000
1379 14 56 17.857 62 16.000
1380 15 60 16.666 62 16.000
1381 16 64 15.625 75 13.333
1382 17 68 14.705 75 13.333
1383 18 72 13.888 75 13.333
1384 19 76 13.157 87 11.428
1385 20 80 12.500 87 11.428
1386 21 84 11.904 87 11.428
1387 22 88 11.363 93 10.666
1388 23 92 10.869 93 10.666
1389 24 96 10.416 100 10.000
1390 25 100 10.000 100 10.000
1391 26 104 9.615 112 8.888
1392 27 108 9.259 112 8.888
1393 28 112 8.928 112 8.888
1394 29 116 8.620 125 8.000
1395 30 120 8.333 125 8.000
1396 31 124 8.064 125 8.000
1397 32 128 7.812 131 7.619
1398 33 132 7.575 150 6.666
1399 34 136 7.352 150 6.666
1400 35 140 7.142 150 6.666
1401 36 144 6.944 150 6.666
1402 37 148 6.756 150 6.666
1403 38 152 6.578 175 5.714
1404 39 156 6.410 175 5.714
1405 40 160 6.250 175 5.714
1406 41 164 6.097 175 5.714
1407 42 168 5.952 175 5.714
1408 43 172 5.813 175 5.714
1409 44 176 5.681 187 5.333
1410 45 180 5.555 187 5.333
1411 46 184 5.434 187 5.333
1412 47 188 5.319 200 5.000
1413 48 192 5.208 200 5.000
1414 49 196 5.102 200 5.000
1415
1416
1417 16.2 Synchronous timings for fast SCSI-2 53C8XX controllers
1418
1419 ----------------------------------------------
1420 Negotiated NCR settings
1421 Factor Period Speed Period Speed
1422 ------ ------ ------ ------ ------
1423 25 100 10.000 100 10.000
1424 26 104 9.615 125 8.000
1425 27 108 9.259 125 8.000
1426 28 112 8.928 125 8.000
1427 29 116 8.620 125 8.000
1428 30 120 8.333 125 8.000
1429 31 124 8.064 125 8.000
1430 32 128 7.812 131 7.619
1431 33 132 7.575 150 6.666
1432 34 136 7.352 150 6.666
1433 35 140 7.142 150 6.666
1434 36 144 6.944 150 6.666
1435 37 148 6.756 150 6.666
1436 38 152 6.578 175 5.714
1437 39 156 6.410 175 5.714
1438 40 160 6.250 175 5.714
1439 41 164 6.097 175 5.714
1440 42 168 5.952 175 5.714
1441 43 172 5.813 175 5.714
1442 44 176 5.681 187 5.333
1443 45 180 5.555 187 5.333
1444 46 184 5.434 187 5.333
1445 47 188 5.319 200 5.000
1446 48 192 5.208 200 5.000
1447 49 196 5.102 200 5.000
1448
1449
1450 17. Serial NVRAM (added by Richard Waltham: dormouse@farsrobt.demon.co.uk)
1451
1452 17.1 Features
1453
1454 Enabling serial NVRAM support enables detection of the serial NVRAM included
1455 on Symbios and some Symbios compatible host adaptors, and Tekram boards. The
1456 serial NVRAM is used by Symbios and Tekram to hold set up parameters for the
1457 host adaptor and its attached drives.
1458
1459 The Symbios NVRAM also holds data on the boot order of host adaptors in a
1460 system with more than one host adaptor. This enables the order of scanning
1461 the cards for drives to be changed from the default used during host adaptor
1462 detection.
1463
1464 This can be done to a limited extent at the moment using "reverse probe" but
1465 this only changes the order of detection of different types of cards. The
1466 NVRAM boot order settings can do this as well as change the order the same
1467 types of cards are scanned in, something "reverse probe" cannot do.
1468
1469 Tekram boards using Symbios chips, DC390W/F/U, which have NVRAM are detected
1470 and this is used to distinguish between Symbios compatible and Tekram host
1471 adaptors. This is used to disable the Symbios compatible "diff" setting
1472 incorrectly set on Tekram boards if the CONFIG_SCSI_53C8XX_SYMBIOS_COMPAT
1473 configuration parameter is set enabling both Symbios and Tekram boards to be
1474 used together with the Symbios cards using all their features, including
1475 "diff" support. ("led pin" support for Symbios compatible cards can remain
1476 enabled when using Tekram cards. It does nothing useful for Tekram host
1477 adaptors but does not cause problems either.)
1478
1479
1480 17.2 Symbios NVRAM layout
1481
1482 typical data at NVRAM address 0x100 (53c810a NVRAM)
1483 -----------------------------------------------------------
1484 00 00
1485 64 01
1486 8e 0b
1487
1488 00 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00
1489
1490 04 00 0f 00 00 10 00 50 00 00 01 00 00 62
1491 04 00 03 00 00 10 00 58 00 00 01 00 00 63
1492 04 00 01 00 00 10 00 48 00 00 01 00 00 61
1493 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1494
1495 0f 00 08 08 64 00 0a 00
1496 0f 00 08 08 64 00 0a 00
1497 0f 00 08 08 64 00 0a 00
1498 0f 00 08 08 64 00 0a 00
1499 0f 00 08 08 64 00 0a 00
1500 0f 00 08 08 64 00 0a 00
1501 0f 00 08 08 64 00 0a 00
1502 0f 00 08 08 64 00 0a 00
1503
1504 0f 00 08 08 64 00 0a 00
1505 0f 00 08 08 64 00 0a 00
1506 0f 00 08 08 64 00 0a 00
1507 0f 00 08 08 64 00 0a 00
1508 0f 00 08 08 64 00 0a 00
1509 0f 00 08 08 64 00 0a 00
1510 0f 00 08 08 64 00 0a 00
1511 0f 00 08 08 64 00 0a 00
1512
1513 00 00 00 00 00 00 00 00
1514 00 00 00 00 00 00 00 00
1515 00 00 00 00 00 00 00 00
1516 00 00 00 00 00 00 00 00
1517 00 00 00 00 00 00 00 00
1518 00 00 00 00 00 00 00 00
1519 00 00 00 00 00 00 00 00
1520 00 00 00 00 00 00 00 00
1521
1522 00 00 00 00 00 00 00 00
1523 00 00 00 00 00 00 00 00
1524 00 00 00 00 00 00 00 00
1525 00 00 00 00 00 00 00 00
1526 00 00 00 00 00 00 00 00
1527 00 00 00 00 00 00 00 00
1528 00 00 00 00 00 00 00 00
1529 00 00 00 00 00 00 00 00
1530
1531 00 00 00 00 00 00 00 00
1532 00 00 00 00 00 00 00 00
1533 00 00 00 00 00 00 00 00
1534
1535 fe fe
1536 00 00
1537 00 00
1538 -----------------------------------------------------------
1539 NVRAM layout details
1540
1541 NVRAM Address 0x000-0x0ff not used
1542 0x100-0x26f initialised data
1543 0x270-0x7ff not used
1544
1545 general layout
1546
1547 header - 6 bytes,
1548 data - 356 bytes (checksum is byte sum of this data)
1549 trailer - 6 bytes
1550 ---
1551 total 368 bytes
1552
1553 data area layout
1554
1555 controller set up - 20 bytes
1556 boot configuration - 56 bytes (4x14 bytes)
1557 device set up - 128 bytes (16x8 bytes)
1558 unused (spare?) - 152 bytes (19x8 bytes)
1559 ---
1560 total 356 bytes
1561
1562 -----------------------------------------------------------
1563 header
1564
1565 00 00 - ?? start marker
1566 64 01 - byte count (lsb/msb excludes header/trailer)
1567 8e 0b - checksum (lsb/msb excludes header/trailer)
1568 -----------------------------------------------------------
1569 controller set up
1570
1571 00 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00
1572 | | | |
1573 | | | -- host ID
1574 | | |
1575 | | --Removable Media Support
1576 | | 0x00 = none
1577 | | 0x01 = Bootable Device
1578 | | 0x02 = All with Media
1579 | |
1580 | --flag bits 2
1581 | 0x00000001= scan order hi->low
1582 | (default 0x00 - scan low->hi)
1583 --flag bits 1
1584 0x00000001 scam enable
1585 0x00000010 parity enable
1586 0x00000100 verbose boot msgs
1587
1588 remaining bytes unknown - they do not appear to change in my
1589 current set up for any of the controllers.
1590
1591 default set up is identical for 53c810a and 53c875 NVRAM
1592 (Removable Media added Symbios BIOS version 4.09)
1593 -----------------------------------------------------------
1594 boot configuration
1595
1596 boot order set by order of the devices in this table
1597
1598 04 00 0f 00 00 10 00 50 00 00 01 00 00 62 -- 1st controller
1599 04 00 03 00 00 10 00 58 00 00 01 00 00 63 2nd controller
1600 04 00 01 00 00 10 00 48 00 00 01 00 00 61 3rd controller
1601 00 00 00 00 00 00 00 00 00 00 00 00 00 00 4th controller
1602 | | | | | | | |
1603 | | | | | | ---- PCI io port adr
1604 | | | | | --0x01 init/scan at boot time
1605 | | | | --PCI device/function number (0xdddddfff)
1606 | | ----- ?? PCI vendor ID (lsb/msb)
1607 ----PCI device ID (lsb/msb)
1608
1609 ?? use of this data is a guess but seems reasonable
1610
1611 remaining bytes unknown - they do not appear to change in my
1612 current set up
1613
1614 default set up is identical for 53c810a and 53c875 NVRAM
1615 -----------------------------------------------------------
1616 device set up (up to 16 devices - includes controller)
1617
1618 0f 00 08 08 64 00 0a 00 - id 0
1619 0f 00 08 08 64 00 0a 00
1620 0f 00 08 08 64 00 0a 00
1621 0f 00 08 08 64 00 0a 00
1622 0f 00 08 08 64 00 0a 00
1623 0f 00 08 08 64 00 0a 00
1624 0f 00 08 08 64 00 0a 00
1625 0f 00 08 08 64 00 0a 00
1626
1627 0f 00 08 08 64 00 0a 00
1628 0f 00 08 08 64 00 0a 00
1629 0f 00 08 08 64 00 0a 00
1630 0f 00 08 08 64 00 0a 00
1631 0f 00 08 08 64 00 0a 00
1632 0f 00 08 08 64 00 0a 00
1633 0f 00 08 08 64 00 0a 00
1634 0f 00 08 08 64 00 0a 00 - id 15
1635 | | | | | |
1636 | | | | ----timeout (lsb/msb)
1637 | | | --synch period (0x?? 40 Mtrans/sec- fast 40) (probably 0x28)
1638 | | | (0x30 20 Mtrans/sec- fast 20)
1639 | | | (0x64 10 Mtrans/sec- fast )
1640 | | | (0xc8 5 Mtrans/sec)
1641 | | | (0x00 asynchronous)
1642 | | -- ?? max sync offset (0x08 in NVRAM on 53c810a)
1643 | | (0x10 in NVRAM on 53c875)
1644 | --device bus width (0x08 narrow)
1645 | (0x10 16 bit wide)
1646 --flag bits
1647 0x00000001 - disconnect enabled
1648 0x00000010 - scan at boot time
1649 0x00000100 - scan luns
1650 0x00001000 - queue tags enabled
1651
1652 remaining bytes unknown - they do not appear to change in my
1653 current set up
1654
1655 ?? use of this data is a guess but seems reasonable
1656 (but it could be max bus width)
1657
1658 default set up for 53c810a NVRAM
1659 default set up for 53c875 NVRAM - bus width - 0x10
1660 - sync offset ? - 0x10
1661 - sync period - 0x30
1662 -----------------------------------------------------------
1663 ?? spare device space (32 bit bus ??)
1664
1665 00 00 00 00 00 00 00 00 (19x8bytes)
1666 .
1667 .
1668 00 00 00 00 00 00 00 00
1669
1670 default set up is identical for 53c810a and 53c875 NVRAM
1671 -----------------------------------------------------------
1672 trailer
1673
1674 fe fe - ? end marker ?
1675 00 00
1676 00 00
1677
1678 default set up is identical for 53c810a and 53c875 NVRAM
1679 -----------------------------------------------------------
1680
1681
1682
1683 17.3 Tekram NVRAM layout
1684
1685 nvram 64x16 (1024 bit)
1686
1687 Drive settings
1688
1689 Drive ID 0-15 (addr 0x0yyyy0 = device setup, yyyy = ID)
1690 (addr 0x0yyyy1 = 0x0000)
1691
1692 x x x x x x x x x x x x x x x x
1693 | | | | | | | | |
1694 | | | | | | | | ----- parity check 0 - off
1695 | | | | | | | | 1 - on
1696 | | | | | | | |
1697 | | | | | | | ------- sync neg 0 - off
1698 | | | | | | | 1 - on
1699 | | | | | | |
1700 | | | | | | --------- disconnect 0 - off
1701 | | | | | | 1 - on
1702 | | | | | |
1703 | | | | | ----------- start cmd 0 - off
1704 | | | | | 1 - on
1705 | | | | |
1706 | | | | -------------- tagged cmds 0 - off
1707 | | | | 1 - on
1708 | | | |
1709 | | | ---------------- wide neg 0 - off
1710 | | | 1 - on
1711 | | |
1712 --------------------------- sync rate 0 - 10.0 Mtrans/sec
1713 1 - 8.0
1714 2 - 6.6
1715 3 - 5.7
1716 4 - 5.0
1717 5 - 4.0
1718 6 - 3.0
1719 7 - 2.0
1720 7 - 2.0
1721 8 - 20.0
1722 9 - 16.7
1723 a - 13.9
1724 b - 11.9
1725
1726 Global settings
1727
1728 Host flags 0 (addr 0x100000, 32)
1729
1730 x x x x x x x x x x x x x x x x
1731 | | | | | | | | | | | |
1732 | | | | | | | | ----------- host ID 0x00 - 0x0f
1733 | | | | | | | |
1734 | | | | | | | ----------------------- support for 0 - off
1735 | | | | | | | > 2 drives 1 - on
1736 | | | | | | |
1737 | | | | | | ------------------------- support drives 0 - off
1738 | | | | | | > 1Gbytes 1 - on
1739 | | | | | |
1740 | | | | | --------------------------- bus reset on 0 - off
1741 | | | | | power on 1 - on
1742 | | | | |
1743 | | | | ----------------------------- active neg 0 - off
1744 | | | | 1 - on
1745 | | | |
1746 | | | -------------------------------- imm seek 0 - off
1747 | | | 1 - on
1748 | | |
1749 | | ---------------------------------- scan luns 0 - off
1750 | | 1 - on
1751 | |
1752 -------------------------------------- removable 0 - disable
1753 as BIOS dev 1 - boot device
1754 2 - all
1755
1756 Host flags 1 (addr 0x100001, 33)
1757
1758 x x x x x x x x x x x x x x x x
1759 | | | | | |
1760 | | | --------- boot delay 0 - 3 sec
1761 | | | 1 - 5
1762 | | | 2 - 10
1763 | | | 3 - 20
1764 | | | 4 - 30
1765 | | | 5 - 60
1766 | | | 6 - 120
1767 | | |
1768 --------------------------- max tag cmds 0 - 2
1769 1 - 4
1770 2 - 8
1771 3 - 16
1772 4 - 32
1773
1774 Host flags 2 (addr 0x100010, 34)
1775
1776 x x x x x x x x x x x x x x x x
1777 |
1778 ----- F2/F6 enable 0 - off ???
1779 1 - on ???
1780
1781 checksum (addr 0x111111)
1782
1783 checksum = 0x1234 - (sum addr 0-63)
1784
1785 ----------------------------------------------------------------------------
1786
1787 default nvram data:
1788
1789 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
1790 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
1791 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
1792 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
1793
1794 0x0f07 0x0400 0x0001 0x0000 0x0000 0x0000 0x0000 0x0000
1795 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000
1796 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000
1797 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0xfbbc
1798
1799
1800 18. Support for Big Endian
1801
1802 The PCI local bus has been primarily designed for x86 architecture.
1803 As a consequence, PCI devices generally expect DWORDS using little endian
1804 byte ordering.
1805
1806 18.1 Big Endian CPU
1807
1808 In order to support NCR chips on a Big Endian architecture the driver has to
1809 perform byte reordering each time it is needed. This feature has been
1810 added to the driver by Cort <cort@cs.nmt.edu> and is available in driver
1811 version 2.5 and later ones. For the moment Big Endian support has only
1812 been tested on Linux/PPC (PowerPC).
1813
1814 18.2 NCR chip in Big Endian mode of operations
1815
1816 It can be read in SYMBIOS documentation that some chips support a special
1817 Big Endian mode, on paper: 53C815, 53C825A, 53C875, 53C875N, 53C895.
1818 This mode of operations is not software-selectable, but needs pin named
1819 BigLit to be pulled-up. Using this mode, most of byte reorderings should
1820 be avoided when the driver is running on a Big Endian CPU.
1821 Driver version 2.5 is also, in theory, ready for this feature.
1822
1823 ===============================================================================
1824 End of NCR53C8XX driver README file