Based on kernel version 5.6.13. Page generated on 2020-05-15 16:46 EST.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 |
The Linux SYM-2 driver documentation file
Written by Gerard Roudier <groudier@free.fr>
21 Rue Carnot
95170 DEUIL LA BARRE - FRANCE
Updated by Matthew Wilcox <matthew@wil.cx>
2004-10-09
===============================================================================
1. Introduction
2. Supported chips and SCSI features
3. Advantages of this driver for newer chips.
3.1 Optimized SCSI SCRIPTS
3.2 New features appeared with the SYM53C896
4. Memory mapped I/O versus normal I/O
5. Tagged command queueing
6. Parity checking
7. Profiling information
8. Control commands
8.1 Set minimum synchronous period
8.2 Set wide size
8.3 Set maximum number of concurrent tagged commands
8.4 Set debug mode
8.5 Set flag (no_disc)
8.6 Set verbose level
8.7 Reset all logical units of a target
8.8 Abort all tasks of all logical units of a target
9. Configuration parameters
10. Boot setup commands
10.1 Syntax
10.2 Available arguments
10.2.1 Default number of tagged commands
10.2.2 Burst max
10.2.3 LED support
10.2.4 Differential mode
10.2.5 IRQ mode
10.2.6 Check SCSI BUS
10.2.7 Suggest a default SCSI id for hosts
10.2.8 Verbosity level
10.2.9 Debug mode
10.2.10 Settle delay
10.2.11 Serial NVRAM
10.2.12 Exclude a host from being attached
10.3 Converting from old options
10.4 SCSI BUS checking boot option
11. SCSI problem troubleshooting
15.1 Problem tracking
15.2 Understanding hardware error reports
12. Serial NVRAM support (by Richard Waltham)
17.1 Features
17.2 Symbios NVRAM layout
17.3 Tekram NVRAM layout
===============================================================================
1. Introduction
This driver supports the whole SYM53C8XX family of PCI-SCSI controllers.
It also support the subset of LSI53C10XX PCI-SCSI controllers that are based
on the SYM53C8XX SCRIPTS language.
It replaces the sym53c8xx+ncr53c8xx driver bundle and shares its core code
with the FreeBSD SYM-2 driver. The `glue' that allows this driver to work
under Linux is contained in 2 files named sym_glue.h and sym_glue.c.
Other drivers files are intended not to depend on the Operating System
on which the driver is used.
The history of this driver can be summarized as follows:
1993: ncr driver written for 386bsd and FreeBSD by:
Wolfgang Stanglmeier <wolf@cologne.de>
Stefan Esser <se@mi.Uni-Koeln.de>
1996: port of the ncr driver to Linux-1.2.13 and rename it ncr53c8xx.
Gerard Roudier
1998: new sym53c8xx driver for Linux based on LOAD/STORE instruction and that
adds full support for the 896 but drops support for early NCR devices.
Gerard Roudier
1999: port of the sym53c8xx driver to FreeBSD and support for the LSI53C1010
33 MHz and 66MHz Ultra-3 controllers. The new driver is named `sym'.
Gerard Roudier
2000: Add support for early NCR devices to FreeBSD `sym' driver.
Break the driver into several sources and separate the OS glue
code from the core code that can be shared among different O/Ses.
Write a glue code for Linux.
Gerard Roudier
2004: Remove FreeBSD compatibility code. Remove support for versions of
Linux before 2.6. Start using Linux facilities.
This README file addresses the Linux version of the driver. Under FreeBSD,
the driver documentation is the sym.8 man page.
Information about new chips is available at LSILOGIC web server:
http://www.lsilogic.com/
SCSI standard documentations are available at T10 site:
http://www.t10.org/
Useful SCSI tools written by Eric Youngdale are part of most Linux
distributions:
scsiinfo: command line tool
scsi-config: TCL/Tk tool using scsiinfo
2. Supported chips and SCSI features
The following features are supported for all chips:
Synchronous negotiation
Disconnection
Tagged command queuing
SCSI parity checking
PCI Master parity checking
Other features depends on chip capabilities.
The driver notably uses optimized SCRIPTS for devices that support
LOAD/STORE and handles PHASE MISMATCH from SCRIPTS for devices that
support the corresponding feature.
The following table shows some characteristics of the chip family.
On board LOAD/STORE HARDWARE
Chip SDMS BIOS Wide SCSI std. Max. sync SCRIPTS PHASE MISMATCH
---- --------- ---- --------- ---------- ---------- --------------
810 N N FAST10 10 MB/s N N
810A N N FAST10 10 MB/s Y N
815 Y N FAST10 10 MB/s N N
825 Y Y FAST10 20 MB/s N N
825A Y Y FAST10 20 MB/s Y N
860 N N FAST20 20 MB/s Y N
875 Y Y FAST20 40 MB/s Y N
875A Y Y FAST20 40 MB/s Y Y
876 Y Y FAST20 40 MB/s Y N
895 Y Y FAST40 80 MB/s Y N
895A Y Y FAST40 80 MB/s Y Y
896 Y Y FAST40 80 MB/s Y Y
897 Y Y FAST40 80 MB/s Y Y
1510D Y Y FAST40 80 MB/s Y Y
1010 Y Y FAST80 160 MB/s Y Y
1010_66* Y Y FAST80 160 MB/s Y Y
* Chip supports 33MHz and 66MHz PCI bus clock.
Summary of other supported features:
Module: allow to load the driver
Memory mapped I/O: increases performance
Control commands: write operations to the proc SCSI file system
Debugging information: written to syslog (expert only)
Scatter / gather
Shared interrupt
Boot setup commands
Serial NVRAM: Symbios and Tekram formats
3. Advantages of this driver for newer chips.
3.1 Optimized SCSI SCRIPTS.
All chips except the 810, 815 and 825, support new SCSI SCRIPTS instructions
named LOAD and STORE that allow to move up to 1 DWORD from/to an IO register
to/from memory much faster that the MOVE MEMORY instruction that is supported
by the 53c7xx and 53c8xx family.
The LOAD/STORE instructions support absolute and DSA relative addressing
modes. The SCSI SCRIPTS had been entirely rewritten using LOAD/STORE instead
of MOVE MEMORY instructions.
Due to the lack of LOAD/STORE SCRIPTS instructions by earlier chips, this
driver also incorporates a different SCRIPTS set based on MEMORY MOVE, in
order to provide support for the entire SYM53C8XX chips family.
3.2 New features appeared with the SYM53C896
Newer chips (see above) allows handling of the phase mismatch context from
SCRIPTS (avoids the phase mismatch interrupt that stops the SCSI processor
until the C code has saved the context of the transfer).
The 896 and 1010 chips support 64 bit PCI transactions and addressing,
while the 895A supports 32 bit PCI transactions and 64 bit addressing.
The SCRIPTS processor of these chips is not true 64 bit, but uses segment
registers for bit 32-63. Another interesting feature is that LOAD/STORE
instructions that address the on-chip RAM (8k) remain internal to the chip.
4. Memory mapped I/O versus normal I/O
Memory mapped I/O has less latency than normal I/O and is the recommended
way for doing IO with PCI devices. Memory mapped I/O seems to work fine on
most hardware configurations, but some poorly designed chipsets may break
this feature. A configuration option is provided for normal I/O to be
used but the driver defaults to MMIO.
5. Tagged command queueing
Queuing more than 1 command at a time to a device allows it to perform
optimizations based on actual head positions and its mechanical
characteristics. This feature may also reduce average command latency.
In order to really gain advantage of this feature, devices must have
a reasonable cache size (No miracle is to be expected for a low-end
hard disk with 128 KB or less).
Some known old SCSI devices do not properly support tagged command queuing.
Generally, firmware revisions that fix this kind of problems are available
at respective vendor web/ftp sites.
All I can say is that I never have had problem with tagged queuing using
this driver and its predecessors. Hard disks that behaved correctly for
me using tagged commands are the following:
- IBM S12 0662
- Conner 1080S
- Quantum Atlas I
- Quantum Atlas II
- Seagate Cheetah I
- Quantum Viking II
- IBM DRVS
- Quantum Atlas IV
- Seagate Cheetah II
If your controller has NVRAM, you can configure this feature per target
from the user setup tool. The Tekram Setup program allows to tune the
maximum number of queued commands up to 32. The Symbios Setup only allows
to enable or disable this feature.
The maximum number of simultaneous tagged commands queued to a device
is currently set to 16 by default. This value is suitable for most SCSI
disks. With large SCSI disks (>= 2GB, cache >= 512KB, average seek time
<= 10 ms), using a larger value may give better performances.
This driver supports up to 255 commands per device, and but using more than
64 is generally not worth-while, unless you are using a very large disk or
disk arrays. It is noticeable that most of recent hard disks seem not to
accept more than 64 simultaneous commands. So, using more than 64 queued
commands is probably just resource wasting.
If your controller does not have NVRAM or if it is managed by the SDMS
BIOS/SETUP, you can configure tagged queueing feature and device queue
depths from the boot command-line. For example:
sym53c8xx=tags:4/t2t3q15-t4q7/t1u0q32
will set tagged commands queue depths as follow:
- target 2 all luns on controller 0 --> 15
- target 3 all luns on controller 0 --> 15
- target 4 all luns on controller 0 --> 7
- target 1 lun 0 on controller 1 --> 32
- all other target/lun --> 4
In some special conditions, some SCSI disk firmwares may return a
QUEUE FULL status for a SCSI command. This behaviour is managed by the
driver using the following heuristic:
- Each time a QUEUE FULL status is returned, tagged queue depth is reduced
to the actual number of disconnected commands.
- Every 200 successfully completed SCSI commands, if allowed by the
current limit, the maximum number of queueable commands is incremented.
Since QUEUE FULL status reception and handling is resource wasting, the
driver notifies by default this problem to user by indicating the actual
number of commands used and their status, as well as its decision on the
device queue depth change.
The heuristic used by the driver in handling QUEUE FULL ensures that the
impact on performances is not too bad. You can get rid of the messages by
setting verbose level to zero, as follow:
1st method: boot your system using 'sym53c8xx=verb:0' option.
2nd method: apply "setverbose 0" control command to the proc fs entry
corresponding to your controller after boot-up.
6. Parity checking
The driver supports SCSI parity checking and PCI bus master parity
checking. These features must be enabled in order to ensure safe
data transfers. Some flawed devices or mother boards may have problems
with parity. The options to defeat parity checking have been removed
from the driver.
7. Profiling information
This driver does not provide profiling information as did its predecessors.
This feature was not this useful and added complexity to the code.
As the driver code got more complex, I have decided to remove everything
that didn't seem actually useful.
8. Control commands
Control commands can be sent to the driver with write operations to
the proc SCSI file system. The generic command syntax is the
following:
echo "<verb> <parameters>" >/proc/scsi/sym53c8xx/0
(assumes controller number is 0)
Using "all" for "<target>" parameter with the commands below will
apply to all targets of the SCSI chain (except the controller).
Available commands:
8.1 Set minimum synchronous period factor
setsync <target> <period factor>
target: target number
period: minimum synchronous period.
Maximum speed = 1000/(4*period factor) except for special
cases below.
Specify a period of 0, to force asynchronous transfer mode.
9 means 12.5 nano-seconds synchronous period
10 means 25 nano-seconds synchronous period
11 means 30 nano-seconds synchronous period
12 means 50 nano-seconds synchronous period
8.2 Set wide size
setwide <target> <size>
target: target number
size: 0=8 bits, 1=16bits
8.3 Set maximum number of concurrent tagged commands
settags <target> <tags>
target: target number
tags: number of concurrent tagged commands
must not be greater than configured (default: 16)
8.4 Set debug mode
setdebug <list of debug flags>
Available debug flags:
alloc: print info about memory allocations (ccb, lcb)
queue: print info about insertions into the command start queue
result: print sense data on CHECK CONDITION status
scatter: print info about the scatter process
scripts: print info about the script binding process
tiny: print minimal debugging information
timing: print timing information of the NCR chip
nego: print information about SCSI negotiations
phase: print information on script interruptions
Use "setdebug" with no argument to reset debug flags.
8.5 Set flag (no_disc)
setflag <target> <flag>
target: target number
For the moment, only one flag is available:
no_disc: not allow target to disconnect.
Do not specify any flag in order to reset the flag. For example:
- setflag 4
will reset no_disc flag for target 4, so will allow it disconnections.
- setflag all
will allow disconnection for all devices on the SCSI bus.
8.6 Set verbose level
setverbose #level
The driver default verbose level is 1. This command allows to change
th driver verbose level after boot-up.
8.7 Reset all logical units of a target
resetdev <target>
target: target number
The driver will try to send a BUS DEVICE RESET message to the target.
8.8 Abort all tasks of all logical units of a target
cleardev <target>
target: target number
The driver will try to send a ABORT message to all the logical units
of the target.
9. Configuration parameters
Under kernel configuration tools (make menuconfig, for example), it is
possible to change some default driver configuration parameters.
If the firmware of all your devices is perfect enough, all the
features supported by the driver can be enabled at start-up. However,
if only one has a flaw for some SCSI feature, you can disable the
support by the driver of this feature at linux start-up and enable
this feature after boot-up only for devices that support it safely.
Configuration parameters:
Use normal IO (default answer: n)
Answer "y" if you suspect your mother board to not allow memory mapped I/O.
May slow down performance a little.
Default tagged command queue depth (default answer: 16)
Entering 0 defaults to tagged commands not being used.
This parameter can be specified from the boot command line.
Maximum number of queued commands (default answer: 32)
This option allows you to specify the maximum number of tagged commands
that can be queued to a device. The maximum supported value is 255.
Synchronous transfers frequency (default answer: 80)
This option allows you to specify the frequency in MHz the driver
will use at boot time for synchronous data transfer negotiations.
0 means "asynchronous data transfers".
10. Boot setup commands
10.1 Syntax
Setup commands can be passed to the driver either at boot time or as
parameters to modprobe, as described in Documentation/admin-guide/kernel-parameters.rst
Example of boot setup command under lilo prompt:
lilo: linux root=/dev/sda2 sym53c8xx.cmd_per_lun=4 sym53c8xx.sync=10 sym53c8xx.debug=0x200
- enable tagged commands, up to 4 tagged commands queued.
- set synchronous negotiation speed to 10 Mega-transfers / second.
- set DEBUG_NEGO flag.
The following command will install the driver module with the same
options as above.
modprobe sym53c8xx cmd_per_lun=4 sync=10 debug=0x200
10.2 Available arguments
10.2.1 Default number of tagged commands
cmd_per_lun=0 (or cmd_per_lun=1) tagged command queuing disabled
cmd_per_lun=#tags (#tags > 1) tagged command queuing enabled
#tags will be truncated to the max queued commands configuration parameter.
10.2.2 Burst max
burst=0 burst disabled
burst=255 get burst length from initial IO register settings.
burst=#x burst enabled (1<<#x burst transfers max)
#x is an integer value which is log base 2 of the burst transfers max.
By default the driver uses the maximum value supported by the chip.
10.2.3 LED support
led=1 enable LED support
led=0 disable LED support
Do not enable LED support if your scsi board does not use SDMS BIOS.
(See 'Configuration parameters')
10.2.4 Differential mode
diff=0 never set up diff mode
diff=1 set up diff mode if BIOS set it
diff=2 always set up diff mode
diff=3 set diff mode if GPIO3 is not set
10.2.5 IRQ mode
irqm=0 always open drain
irqm=1 same as initial settings (assumed BIOS settings)
irqm=2 always totem pole
10.2.6 Check SCSI BUS
buschk=<option bits>
Available option bits:
0x0: No check.
0x1: Check and do not attach the controller on error.
0x2: Check and just warn on error.
10.2.7 Suggest a default SCSI id for hosts
hostid=255 no id suggested.
hostid=#x (0 < x < 7) x suggested for hosts SCSI id.
If a host SCSI id is available from the NVRAM, the driver will ignore
any value suggested as boot option. Otherwise, if a suggested value
different from 255 has been supplied, it will use it. Otherwise, it will
try to deduce the value previously set in the hardware and use value
7 if the hardware value is zero.
10.2.8 Verbosity level
verb=0 minimal
verb=1 normal
verb=2 too much
10.2.9 Debug mode
debug=0 clear debug flags
debug=#x set debug flags
#x is an integer value combining the following power-of-2 values:
DEBUG_ALLOC 0x1
DEBUG_PHASE 0x2
DEBUG_POLL 0x4
DEBUG_QUEUE 0x8
DEBUG_RESULT 0x10
DEBUG_SCATTER 0x20
DEBUG_SCRIPT 0x40
DEBUG_TINY 0x80
DEBUG_TIMING 0x100
DEBUG_NEGO 0x200
DEBUG_TAGS 0x400
DEBUG_FREEZE 0x800
DEBUG_RESTART 0x1000
You can play safely with DEBUG_NEGO. However, some of these flags may
generate bunches of syslog messages.
10.2.10 Settle delay
settle=n delay for n seconds
After a bus reset, the driver will delay for n seconds before talking
to any device on the bus. The default is 3 seconds and safe mode will
default it to 10.
10.2.11 Serial NVRAM
NB: option not currently implemented.
nvram=n do not look for serial NVRAM
nvram=y test controllers for onboard serial NVRAM
(alternate binary form)
nvram=<bits options>
0x01 look for NVRAM (equivalent to nvram=y)
0x02 ignore NVRAM "Synchronous negotiation" parameters for all devices
0x04 ignore NVRAM "Wide negotiation" parameter for all devices
0x08 ignore NVRAM "Scan at boot time" parameter for all devices
0x80 also attach controllers set to OFF in the NVRAM (sym53c8xx only)
10.2.12 Exclude a host from being attached
excl=<io_address>,...
Prevent host at a given io address from being attached.
For example 'excl=0xb400,0xc000' indicate to the
driver not to attach hosts at address 0xb400 and 0xc000.
10.3 Converting from old style options
Previously, the sym2 driver accepted arguments of the form
sym53c8xx=tags:4,sync:10,debug:0x200
As a result of the new module parameters, this is no longer available.
Most of the options have remained the same, but tags has become
cmd_per_lun to reflect its different purposes. The sample above would
be specified as:
modprobe sym53c8xx cmd_per_lun=4 sync=10 debug=0x200
or on the kernel boot line as:
sym53c8xx.cmd_per_lun=4 sym53c8xx.sync=10 sym53c8xx.debug=0x200
10.4 SCSI BUS checking boot option.
When this option is set to a non-zero value, the driver checks SCSI lines
logic state, 100 micro-seconds after having asserted the SCSI RESET line.
The driver just reads SCSI lines and checks all lines read FALSE except RESET.
Since SCSI devices shall release the BUS at most 800 nano-seconds after SCSI
RESET has been asserted, any signal to TRUE may indicate a SCSI BUS problem.
Unfortunately, the following common SCSI BUS problems are not detected:
- Only 1 terminator installed.
- Misplaced terminators.
- Bad quality terminators.
On the other hand, either bad cabling, broken devices, not conformant
devices, ... may cause a SCSI signal to be wrong when te driver reads it.
15. SCSI problem troubleshooting
15.1 Problem tracking
Most SCSI problems are due to a non conformant SCSI bus or too buggy
devices. If unfortunately you have SCSI problems, you can check the
following things:
- SCSI bus cables
- terminations at both end of the SCSI chain
- linux syslog messages (some of them may help you)
If you do not find the source of problems, you can configure the
driver or devices in the NVRAM with minimal features.
- only asynchronous data transfers
- tagged commands disabled
- disconnections not allowed
Now, if your SCSI bus is ok, your system has every chance to work
with this safe configuration but performances will not be optimal.
If it still fails, then you can send your problem description to
appropriate mailing lists or news-groups. Send me a copy in order to
be sure I will receive it. Obviously, a bug in the driver code is
possible.
My current email address: Gerard Roudier <groudier@free.fr>
Allowing disconnections is important if you use several devices on
your SCSI bus but often causes problems with buggy devices.
Synchronous data transfers increases throughput of fast devices like
hard disks. Good SCSI hard disks with a large cache gain advantage of
tagged commands queuing.
15.2 Understanding hardware error reports
When the driver detects an unexpected error condition, it may display a
message of the following pattern.
sym0:1: ERROR (0:48) (1-21-65) (f/95/0) @ (script 7c0:19000000).
sym0: script cmd = 19000000
sym0: regdump: da 10 80 95 47 0f 01 07 75 01 81 21 80 01 09 00.
Some fields in such a message may help you understand the cause of the
problem, as follows:
sym0:1: ERROR (0:48) (1-21-65) (f/95/0) @ (script 7c0:19000000).
.....A.........B.C....D.E..F....G.H..I.......J.....K...L.......
Field A : target number.
SCSI ID of the device the controller was talking with at the moment the
error occurs.
Field B : DSTAT io register (DMA STATUS)
Bit 0x40 : MDPE Master Data Parity Error
Data parity error detected on the PCI BUS.
Bit 0x20 : BF Bus Fault
PCI bus fault condition detected
Bit 0x01 : IID Illegal Instruction Detected
Set by the chip when it detects an Illegal Instruction format
on some condition that makes an instruction illegal.
Bit 0x80 : DFE Dma Fifo Empty
Pure status bit that does not indicate an error.
If the reported DSTAT value contains a combination of MDPE (0x40),
BF (0x20), then the cause may be likely due to a PCI BUS problem.
Field C : SIST io register (SCSI Interrupt Status)
Bit 0x08 : SGE SCSI GROSS ERROR
Indicates that the chip detected a severe error condition
on the SCSI BUS that prevents the SCSI protocol from functioning
properly.
Bit 0x04 : UDC Unexpected Disconnection
Indicates that the device released the SCSI BUS when the chip
was not expecting this to happen. A device may behave so to
indicate the SCSI initiator that an error condition not reportable using the SCSI protocol has occurred.
Bit 0x02 : RST SCSI BUS Reset
Generally SCSI targets do not reset the SCSI BUS, although any
device on the BUS can reset it at any time.
Bit 0x01 : PAR Parity
SCSI parity error detected.
On a faulty SCSI BUS, any error condition among SGE (0x08), UDC (0x04) and
PAR (0x01) may be detected by the chip. If your SCSI system sometimes
encounters such error conditions, especially SCSI GROSS ERROR, then a SCSI
BUS problem is likely the cause of these errors.
For fields D,E,F,G and H, you may look into the sym53c8xx_defs.h file
that contains some minimal comments on IO register bits.
Field D : SOCL Scsi Output Control Latch
This register reflects the state of the SCSI control lines the
chip want to drive or compare against.
Field E : SBCL Scsi Bus Control Lines
Actual value of control lines on the SCSI BUS.
Field F : SBDL Scsi Bus Data Lines
Actual value of data lines on the SCSI BUS.
Field G : SXFER SCSI Transfer
Contains the setting of the Synchronous Period for output and
the current Synchronous offset (offset 0 means asynchronous).
Field H : SCNTL3 Scsi Control Register 3
Contains the setting of timing values for both asynchronous and
synchronous data transfers.
Field I : SCNTL4 Scsi Control Register 4
Only meaningful for 53C1010 Ultra3 controllers.
Understanding Fields J, K, L and dumps requires to have good knowledge of
SCSI standards, chip cores functionnals and internal driver data structures.
You are not required to decode and understand them, unless you want to help
maintain the driver code.
17. Serial NVRAM (added by Richard Waltham: dormouse@farsrobt.demon.co.uk)
17.1 Features
Enabling serial NVRAM support enables detection of the serial NVRAM included
on Symbios and some Symbios compatible host adaptors, and Tekram boards. The
serial NVRAM is used by Symbios and Tekram to hold set up parameters for the
host adaptor and its attached drives.
The Symbios NVRAM also holds data on the boot order of host adaptors in a
system with more than one host adaptor. This information is no longer used
as it's fundamentally incompatible with the hotplug PCI model.
Tekram boards using Symbios chips, DC390W/F/U, which have NVRAM are detected
and this is used to distinguish between Symbios compatible and Tekram host
adaptors. This is used to disable the Symbios compatible "diff" setting
incorrectly set on Tekram boards if the CONFIG_SCSI_53C8XX_SYMBIOS_COMPAT
configuration parameter is set enabling both Symbios and Tekram boards to be
used together with the Symbios cards using all their features, including
"diff" support. ("led pin" support for Symbios compatible cards can remain
enabled when using Tekram cards. It does nothing useful for Tekram host
adaptors but does not cause problems either.)
The parameters the driver is able to get from the NVRAM depend on the
data format used, as follow:
Tekram format Symbios format
General and host parameters
Boot order N Y
Host SCSI ID Y Y
SCSI parity checking Y Y
Verbose boot messages N Y
SCSI devices parameters
Synchronous transfer speed Y Y
Wide 16 / Narrow Y Y
Tagged Command Queuing enabled Y Y
Disconnections enabled Y Y
Scan at boot time N Y
In order to speed up the system boot, for each device configured without
the "scan at boot time" option, the driver forces an error on the
first TEST UNIT READY command received for this device.
17.2 Symbios NVRAM layout
typical data at NVRAM address 0x100 (53c810a NVRAM)
-----------------------------------------------------------
00 00
64 01
8e 0b
00 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00
04 00 0f 00 00 10 00 50 00 00 01 00 00 62
04 00 03 00 00 10 00 58 00 00 01 00 00 63
04 00 01 00 00 10 00 48 00 00 01 00 00 61
00 00 00 00 00 00 00 00 00 00 00 00 00 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
fe fe
00 00
00 00
-----------------------------------------------------------
NVRAM layout details
NVRAM Address 0x000-0x0ff not used
0x100-0x26f initialised data
0x270-0x7ff not used
general layout
header - 6 bytes,
data - 356 bytes (checksum is byte sum of this data)
trailer - 6 bytes
---
total 368 bytes
data area layout
controller set up - 20 bytes
boot configuration - 56 bytes (4x14 bytes)
device set up - 128 bytes (16x8 bytes)
unused (spare?) - 152 bytes (19x8 bytes)
---
total 356 bytes
-----------------------------------------------------------
header
00 00 - ?? start marker
64 01 - byte count (lsb/msb excludes header/trailer)
8e 0b - checksum (lsb/msb excludes header/trailer)
-----------------------------------------------------------
controller set up
00 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00
| | | |
| | | -- host ID
| | |
| | --Removable Media Support
| | 0x00 = none
| | 0x01 = Bootable Device
| | 0x02 = All with Media
| |
| --flag bits 2
| 0x00000001= scan order hi->low
| (default 0x00 - scan low->hi)
--flag bits 1
0x00000001 scam enable
0x00000010 parity enable
0x00000100 verbose boot msgs
remaining bytes unknown - they do not appear to change in my
current set up for any of the controllers.
default set up is identical for 53c810a and 53c875 NVRAM
(Removable Media added Symbios BIOS version 4.09)
-----------------------------------------------------------
boot configuration
boot order set by order of the devices in this table
04 00 0f 00 00 10 00 50 00 00 01 00 00 62 -- 1st controller
04 00 03 00 00 10 00 58 00 00 01 00 00 63 2nd controller
04 00 01 00 00 10 00 48 00 00 01 00 00 61 3rd controller
00 00 00 00 00 00 00 00 00 00 00 00 00 00 4th controller
| | | | | | | |
| | | | | | ---- PCI io port adr
| | | | | --0x01 init/scan at boot time
| | | | --PCI device/function number (0xdddddfff)
| | ----- ?? PCI vendor ID (lsb/msb)
----PCI device ID (lsb/msb)
?? use of this data is a guess but seems reasonable
remaining bytes unknown - they do not appear to change in my
current set up
default set up is identical for 53c810a and 53c875 NVRAM
-----------------------------------------------------------
device set up (up to 16 devices - includes controller)
0f 00 08 08 64 00 0a 00 - id 0
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00 - id 15
| | | | | |
| | | | ----timeout (lsb/msb)
| | | --synch period (0x?? 40 Mtrans/sec- fast 40) (probably 0x28)
| | | (0x30 20 Mtrans/sec- fast 20)
| | | (0x64 10 Mtrans/sec- fast )
| | | (0xc8 5 Mtrans/sec)
| | | (0x00 asynchronous)
| | -- ?? max sync offset (0x08 in NVRAM on 53c810a)
| | (0x10 in NVRAM on 53c875)
| --device bus width (0x08 narrow)
| (0x10 16 bit wide)
--flag bits
0x00000001 - disconnect enabled
0x00000010 - scan at boot time
0x00000100 - scan luns
0x00001000 - queue tags enabled
remaining bytes unknown - they do not appear to change in my
current set up
?? use of this data is a guess but seems reasonable
(but it could be max bus width)
default set up for 53c810a NVRAM
default set up for 53c875 NVRAM - bus width - 0x10
- sync offset ? - 0x10
- sync period - 0x30
-----------------------------------------------------------
?? spare device space (32 bit bus ??)
00 00 00 00 00 00 00 00 (19x8bytes)
.
.
00 00 00 00 00 00 00 00
default set up is identical for 53c810a and 53c875 NVRAM
-----------------------------------------------------------
trailer
fe fe - ? end marker ?
00 00
00 00
default set up is identical for 53c810a and 53c875 NVRAM
-----------------------------------------------------------
17.3 Tekram NVRAM layout
nvram 64x16 (1024 bit)
Drive settings
Drive ID 0-15 (addr 0x0yyyy0 = device setup, yyyy = ID)
(addr 0x0yyyy1 = 0x0000)
x x x x x x x x x x x x x x x x
| | | | | | | | |
| | | | | | | | ----- parity check 0 - off
| | | | | | | | 1 - on
| | | | | | | |
| | | | | | | ------- sync neg 0 - off
| | | | | | | 1 - on
| | | | | | |
| | | | | | --------- disconnect 0 - off
| | | | | | 1 - on
| | | | | |
| | | | | ----------- start cmd 0 - off
| | | | | 1 - on
| | | | |
| | | | -------------- tagged cmds 0 - off
| | | | 1 - on
| | | |
| | | ---------------- wide neg 0 - off
| | | 1 - on
| | |
--------------------------- sync rate 0 - 10.0 Mtrans/sec
1 - 8.0
2 - 6.6
3 - 5.7
4 - 5.0
5 - 4.0
6 - 3.0
7 - 2.0
7 - 2.0
8 - 20.0
9 - 16.7
a - 13.9
b - 11.9
Global settings
Host flags 0 (addr 0x100000, 32)
x x x x x x x x x x x x x x x x
| | | | | | | | | | | |
| | | | | | | | ----------- host ID 0x00 - 0x0f
| | | | | | | |
| | | | | | | ----------------------- support for 0 - off
| | | | | | | > 2 drives 1 - on
| | | | | | |
| | | | | | ------------------------- support drives 0 - off
| | | | | | > 1Gbytes 1 - on
| | | | | |
| | | | | --------------------------- bus reset on 0 - off
| | | | | power on 1 - on
| | | | |
| | | | ----------------------------- active neg 0 - off
| | | | 1 - on
| | | |
| | | -------------------------------- imm seek 0 - off
| | | 1 - on
| | |
| | ---------------------------------- scan luns 0 - off
| | 1 - on
| |
-------------------------------------- removable 0 - disable
as BIOS dev 1 - boot device
2 - all
Host flags 1 (addr 0x100001, 33)
x x x x x x x x x x x x x x x x
| | | | | |
| | | --------- boot delay 0 - 3 sec
| | | 1 - 5
| | | 2 - 10
| | | 3 - 20
| | | 4 - 30
| | | 5 - 60
| | | 6 - 120
| | |
--------------------------- max tag cmds 0 - 2
1 - 4
2 - 8
3 - 16
4 - 32
Host flags 2 (addr 0x100010, 34)
x x x x x x x x x x x x x x x x
|
----- F2/F6 enable 0 - off ???
1 - on ???
checksum (addr 0x111111)
checksum = 0x1234 - (sum addr 0-63)
----------------------------------------------------------------------------
default nvram data:
0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
0x0f07 0x0400 0x0001 0x0000 0x0000 0x0000 0x0000 0x0000
0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000
0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000
0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0xfbbc
===============================================================================
End of Linux SYM-2 driver documentation file
|