1The Linux NCR53C8XX/SYM53C8XX drivers README file 2 3Written by Gerard Roudier <groudier@free.fr> 421 Rue Carnot 595170 DEUIL LA BARRE - FRANCE 6 729 May 1999 8=============================================================================== 9 101. Introduction 112. Supported chips and SCSI features 123. 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) 154. Memory mapped I/O versus normal I/O 165. Tagged command queueing 176. Parity checking 187. Profiling information 198. 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 309. Configuration parameters 3110. 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 6111. Some constants and flags of the ncr53c8xx.h header file 6212. Installation 6313. Architecture dependent features 6414. 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 7015. SCSI problem troubleshooting 71 15.1 Problem tracking 72 15.2 Understanding hardware error reports 7316. 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 7617. Serial NVRAM support (by Richard Waltham) 77 17.1 Features 78 17.2 Symbios NVRAM layout 79 17.3 Tekram NVRAM layout 8018. Support for Big Endian 81 18.1 Big Endian CPU 82 18.2 NCR chip in Big Endian mode of operations 83 84=============================================================================== 85 861. Introduction 87 88The initial Linux ncr53c8xx driver has been a port of the ncr driver from 89FreeBSD that has been achieved in November 1995 by: 90 Gerard Roudier <groudier@free.fr> 91 92The 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 96It 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 106You can find technical information about the NCR 8xx family in the 107PCI-HOWTO written by Michael Will and in the SCSI-HOWTO written by 108Drew Eckhardt. 109 110Information about new chips is available at LSILOGIC web server: 111 112 http://www.lsilogic.com/ 113 114SCSI standard documentations are available at SYMBIOS ftp server: 115 116 ftp://ftp.symbios.com/ 117 118Useful 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 123These tools are not ALPHA but quite clean and work quite well. 124It is essential you have the 'scsiinfo' package. 125 126This short documentation describes the features of the generic and enhanced 127drivers, configuration parameters and control commands available through 128the proc SCSI file system read / write operations. 129 130This driver has been tested OK with linux/i386, Linux/Alpha and Linux/PPC. 131 132Latest driver version and patches are available at: 133 134 ftp://ftp.tux.org/pub/people/gerard-roudier 135or 136 ftp://ftp.symbios.com/mirror/ftp.tux.org/pub/tux/roudier/drivers 137 138I am not a native speaker of English and there are probably lots of 139mistakes in this README file. Any help will be welcome. 140 141 1422. Supported chips and SCSI features 143 144The 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 153following table shows some characteristics of NCR 8xx family chips 154and what drivers support them. 155 156 Supported by Supported by 157 On board the generic the enhanced 158Chip SDMS BIOS Wide SCSI std. Max. sync driver driver 159---- --------- ---- --------- ---------- ------------ ------------- 160810 N N FAST10 10 MB/s Y N 161810A N N FAST10 10 MB/s Y Y 162815 Y N FAST10 10 MB/s Y N 163825 Y Y FAST10 20 MB/s Y N 164825A Y Y FAST10 20 MB/s Y Y 165860 N N FAST20 20 MB/s Y Y 166875 Y Y FAST20 40 MB/s Y Y 167876 Y Y FAST20 40 MB/s Y Y 168895 Y Y FAST40 80 MB/s Y Y 169895A Y Y FAST40 80 MB/s Y Y 170896 Y Y FAST40 80 MB/s Y Y 171897 Y Y FAST40 80 MB/s Y Y 1721510D Y Y FAST40 80 MB/s Y Y 1731010 Y Y FAST80 160 MB/s N Y 1741010_66* Y Y FAST80 160 MB/s N Y 175 176* Chip supports 33MHz and 66MHz PCI buses. 177 178 179Summary of other supported features: 180 181Module: allow to load the driver 182Memory mapped I/O: increases performance 183Profiling information: read operations from the proc SCSI file system 184Control commands: write operations to the proc SCSI file system 185Debugging information: written to syslog (expert only) 186Scatter / gather 187Shared interrupt 188Boot setup commands 189Serial NVRAM: Symbios and Tekram formats 190 191 1923. Advantages of the enhanced 896 driver 193 1943.1 Optimized SCSI SCRIPTS. 195 196The 810A, 825A, 875, 895, 896 and 895A support new SCSI SCRIPTS instructions 197named LOAD and STORE that allow to move up to 1 DWORD from/to an IO register 198to/from memory much faster that the MOVE MEMORY instruction that is supported 199by the 53c7xx and 53c8xx family. 200The LOAD/STORE instructions support absolute and DSA relative addressing 201modes. The SCSI SCRIPTS had been entirely rewritten using LOAD/STORE instead 202of MOVE MEMORY instructions. 203 2043.2 New features of the SYM53C896 (64 bit PCI dual LVD SCSI controller) 205 206The 896 and the 895A allows handling of the phase mismatch context from 207SCRIPTS (avoids the phase mismatch interrupt that stops the SCSI processor 208until the C code has saved the context of the transfer). 209Implementing this without using LOAD/STORE instructions would be painful 210and I didn't even want to try it. 211 212The 896 chip supports 64 bit PCI transactions and addressing, while the 213895A supports 32 bit PCI transactions and 64 bit addressing. 214The SCRIPTS processor of these chips is not true 64 bit, but uses segment 215registers for bit 32-63. Another interesting feature is that LOAD/STORE 216instructions that address the on-chip RAM (8k) remain internal to the chip. 217 218Due to the use of LOAD/STORE SCRIPTS instructions, this driver does not 219support the following chips: 220- SYM53C810 revision < 0x10 (16) 221- SYM53C815 all revisions 222- SYM53C825 revision < 0x10 (16) 223 2244. Memory mapped I/O versus normal I/O 225 226Memory mapped I/O has less latency than normal I/O. Since 227linux-1.3.x, memory mapped I/O is used rather than normal I/O. Memory 228mapped I/O seems to work fine on most hardware configurations, but 229some poorly designed motherboards may break this feature. 230 231The configuration option CONFIG_SCSI_NCR53C8XX_IOMAPPED forces the 232driver to use normal I/O in all cases. 233 234 2355. Tagged command queueing 236 237Queuing more than 1 command at a time to a device allows it to perform 238optimizations based on actual head positions and its mechanical 239characteristics. This feature may also reduce average command latency. 240In order to really gain advantage of this feature, devices must have 241a reasonable cache size (No miracle is to be expected for a low-end 242hard disk with 128 KB or less). 243Some known SCSI devices do not properly support tagged command queuing. 244Generally, firmware revisions that fix this kind of problems are available 245at respective vendor web/ftp sites. 246All I can say is that the hard disks I use on my machines behave well with 247this driver with tagged command queuing enabled: 248 249- IBM S12 0662 250- Conner 1080S 251- Quantum Atlas I 252- Quantum Atlas II 253 254If your controller has NVRAM, you can configure this feature per target 255from the user setup tool. The Tekram Setup program allows to tune the 256maximum number of queued commands up to 32. The Symbios Setup only allows 257to enable or disable this feature. 258 259The maximum number of simultaneous tagged commands queued to a device 260is currently set to 8 by default. This value is suitable for most SCSI 261disks. With large SCSI disks (>= 2GB, cache >= 512KB, average seek time 262<= 10 ms), using a larger value may give better performances. 263 264The sym53c8xx driver supports up to 255 commands per device, and the 265generic ncr53c8xx driver supports up to 64, but using more than 32 is 266generally not worth-while, unless you are using a very large disk or disk 267array. It is noticeable that most of recent hard disks seem not to accept 268more than 64 simultaneous commands. So, using more than 64 queued commands 269is probably just resource wasting. 270 271If your controller does not have NVRAM or if it is managed by the SDMS 272BIOS/SETUP, you can configure tagged queueing feature and device queue 273depths from the boot command-line. For example: 274 275 ncr53c8xx=tags:4/t2t3q15-t4q7/t1u0q32 276 277will 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 285In some special conditions, some SCSI disk firmwares may return a 286QUEUE FULL status for a SCSI command. This behaviour is managed by the 287driver 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 295Since QUEUE FULL status reception and handling is resource wasting, the 296driver notifies by default this problem to user by indicating the actual 297number of commands used and their status, as well as its decision on the 298device queue depth change. 299The heuristic used by the driver in handling QUEUE FULL ensures that the 300impact on performances is not too bad. You can get rid of the messages by 301setting verbose level to zero, as follow: 302 3031st method: boot your system using 'ncr53c8xx=verb:0' option. 3042nd method: apply "setverbose 0" control command to the proc fs entry 305 corresponding to your controller after boot-up. 306 3076. Parity checking 308 309The driver supports SCSI parity checking and PCI bus master parity 310checking. These features must be enabled in order to ensure safe data 311transfers. However, some flawed devices or mother boards will have 312problems with parity. You can disable either PCI parity or SCSI parity 313checking by entering appropriate options from the boot command line. 314(See 10: Boot setup commands). 315 3167. Profiling information 317 318Profiling information is available through the proc SCSI file system. 319Since gathering profiling information may impact performances, this 320feature is disabled by default and requires a compilation configuration 321option to be set to Y. 322 323The device associated with a host has the following pathname: 324 325 /proc/scsi/ncr53c8xx/N (N=0,1,2 ....) 326 327Generally, only 1 board is used on hardware configuration, and that device is: 328 /proc/scsi/ncr53c8xx/0 329 330However, if the driver has been made as module, the number of the 331hosts is incremented each time the driver is loaded. 332 333In order to display profiling information, just enter: 334 335 cat /proc/scsi/ncr53c8xx/0 336 337and you will get something like the following text: 338 339------------------------------------------------------- 340General 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 345Profiling 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 358General information is easy to understand. The device ID and the 359revision ID identify the SCSI chip as follows: 360 361Chip Device id Revision Id 362---- --------- ----------- 363810 0x1 < 0x10 364810A 0x1 >= 0x10 365815 0x4 366825 0x3 < 0x10 367860 0x6 368825A 0x3 >= 0x10 369875 0xf 370895 0xc 371 372The profiling information is updated upon completion of SCSI commands. 373A data structure is allocated and zeroed when the host adapter is 374attached. So, if the driver is a module, the profile counters are 375cleared each time the driver is loaded. The "clearprof" command 376allows you to clear these counters at any time. 377 378The following counters are available: 379 380("num" prefix means "number of", 381"ms" means milli-seconds) 382 383num_trans 384 Number of completed commands 385 Example above: 18014 completed commands 386 387num_kbytes 388 Number of kbytes transferred 389 Example above: 671 MB transferred 390 391num_disc 392 Number of SCSI disconnections 393 Example above: 25763 SCSI disconnections 394 395num_break 396 number of script interruptions (phase mismatch) 397 Example above: 1673 script interruptions 398 399num_int 400 Number of interrupts other than "on the fly" 401 Example above: 1685 interruptions not "on the fly" 402 403num_fly 404 Number of interrupts "on the fly" 405 Example above: 18038 interruptions "on the fly" 406 407ms_setup 408 Elapsed time for SCSI commands setups 409 Example above: 4.94 seconds 410 411ms_data 412 Elapsed time for data transfers 413 Example above: 369.94 seconds spent for data transfer 414 415ms_disc 416 Elapsed time for SCSI disconnections 417 Example above: 183.09 seconds spent disconnected 418 419ms_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 424Due to the 1/100 second tick of the system clock, "ms_post" time may 425be wrong. 426 427In the example above, we got 18038 interrupts "on the fly" and only 4281673 script breaks generally due to disconnections inside a segment 429of the scatter list. 430 431 4328. Control commands 433 434Control commands can be sent to the driver with write operations to 435the proc SCSI file system. The generic command syntax is the 436following: 437 438 echo "<verb> <parameters>" >/proc/scsi/ncr53c8xx/0 439 (assumes controller number is 0) 440 441Using "all" for "<target>" parameter with the commands below will 442apply to all targets of the SCSI chain (except the controller). 443 444Available commands: 445 4468.1 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 4618.2 Set wide size 462 463 setwide <target> <size> 464 465 target: target number 466 size: 0=8 bits, 1=16bits 467 4688.3 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 4768.4 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 4888.5 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 5068.6 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 5158.7 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 5328.8 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 5398.9 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 5478.10 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 5579. Configuration parameters 558 559If the firmware of all your devices is perfect enough, all the 560features supported by the driver can be enabled at start-up. However, 561if only one has a flaw for some SCSI feature, you can disable the 562support by the driver of this feature at linux start-up and enable 563this feature after boot-up only for devices that support it safely. 564 565CONFIG_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 572CONFIG_SCSI_NCR53C8XX_DEFAULT_TAGS (default answer: 8) 573 Default tagged command queue depth. 574 575CONFIG_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 579CONFIG_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 585CONFIG_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 590CONFIG_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 595CONFIG_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 607CONFIG_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 62010. Boot setup commands 621 62210.1 Syntax 623 624Setup commands can be passed to the driver either at boot time or as a 625string variable using 'insmod'. 626 627A boot setup command for the ncr53c8xx (sym53c8xx) driver begins with the 628driver name "ncr53c8xx="(sym53c8xx). The kernel syntax parser then expects 629an optional list of integers separated with comma followed by an optional 630list of comma-separated strings. Example of boot setup command under lilo 631prompt: 632 633lilo: 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 639Since comma seems not to be allowed when defining a string variable using 640'insmod', the driver also accepts <space> as option separator. 641The following command will install driver module with the same options as 642above. 643 644 insmod ncr53c8xx.o ncr53c8xx="tags:4 sync:10 debug:0x200" 645 646For the moment, the integer list of arguments is discarded by the driver. 647It will be used in the future in order to allow a per controller setup. 648 649Each string argument must be specified as "keyword:value". Only lower-case 650characters and digits are allowed. 651 652In a system that contains multiple 53C8xx adapters insmod will install the 653specified driver on each adapter. To exclude a chip use the 'excl' keyword. 654 655The sequence of commands, 656 657 insmod sym53c8xx sym53c8xx=excl:0x1400 658 insmod ncr53c8xx 659 660installs the sym53c8xx driver on all adapters except the one at IO port 661address 0x1400 and then installs the ncr53c8xx driver to the adapter at IO 662port address 0x1400. 663 664 66510.2 Available arguments 666 66710.2.1 Master parity checking 668 mpar:y enabled 669 mpar:n disabled 670 67110.2.2 Scsi parity checking 672 spar:y enabled 673 spar:n disabled 674 67510.2.3 Scsi disconnections 676 disc:y enabled 677 disc:n disabled 678 67910.2.4 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 68910.2.5 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 69710.2.6 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 71110.2.7 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 72210.2.8 Negotiate synchronous with all devices 723 (force sync nego) 724 fsn:y enabled 725 fsn:n disabled 726 72710.2.9 Verbosity level 728 verb:0 minimal 729 verb:1 normal 730 verb:2 too much 731 73210.2.10 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 75310.2.11 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 76410.2.12 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 77010.2.13 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 77810.2.14 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 78410.2.15 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 79210.2.16 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 79710.2.17 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 80810.2.18 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 81910.2.19 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 82810.2.20 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 83510.2.21 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 84510.2.22 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 855Boot 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 88010.3 Advised boot setup commands 881 882If the driver has been configured with default options, the equivalent 883boot 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 888For an installation diskette or a safe but not fast system, 889boot 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 896My 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 901The 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" 903to your boot setup command in order to check the actual setup the driver is 904using. 905 90610.4 PCI configuration fix-up boot option 907 908pcifix:<option bits> 909 910Available 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 914Use 'pcifix:3' in order to allow the driver to fix both PCI features. 915 916These options only apply to new SYMBIOS chips 810A, 825A, 860, 875 917and 895 and are only supported for Pentium and 486 class processors. 918Recent SYMBIOS 53C8XX scsi processors are able to use PCI read multiple 919and PCI write and invalidate commands. These features require the 920cache line size register to be properly set in the PCI configuration 921space of the chips. On the other hand, chips will use PCI write and 922invalidate commands only if the corresponding bit is set to 1 in the 923PCI command register. 924 925Not all PCI bioses set the PCI cache line register and the PCI write and 926invalidate bit in the PCI configuration space of 53C8XX chips. 927Optimized PCI accesses may be broken for some PCI/memory controllers or 928make problems with some PCI boards. 929 930This fix-up worked flawlessly on my previous system. 931(MB Triton HX / 53C875 / 53C810A) 932I use these options at my own risks as you will do if you decide to 933use them too. 934 935 93610.5 Serial NVRAM support boot option 937 938nvram:n do not look for serial NVRAM 939nvram:y test controllers for onboard serial NVRAM 940 941This option can also been entered as an hexadecimal value that allows 942to control what information the driver will get from the NVRAM and what 943information it will ignore. 944For details see '17. Serial NVRAM support'. 945 946When this option is enabled, the driver tries to detect all boards using 947a Serial NVRAM. This memory is used to hold user set up parameters. 948 949The parameters the driver is able to get from the NVRAM depend on the 950data format used, as follow: 951 952 Tekram format Symbios format 953General 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 958SCSI 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 965In order to speed up the system boot, for each device configured without 966the "scan at boot time" option, the driver forces an error on the 967first TEST UNIT READY command received for this device. 968 969Some SDMS BIOS revisions seem to be unable to boot cleanly with very fast 970hard disks. In such a situation you cannot configure the NVRAM with 971optimized parameters value. 972 973The 'nvram' boot option can be entered in hexadecimal form in order 974to ignore some options configured in the NVRAM, as follow: 975 976mvram=<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 983Option 0x80 is only supported by the sym53c8xx driver and is disabled by 984default. Result is that, by default (option not set), the sym53c8xx driver 985will not attach controllers set to OFF in the NVRAM. 986 987The ncr53c8xx always tries to attach all the controllers. Option 0x80 has 988not been added to the ncr53c8xx driver, since it has been reported to 989confuse users who use this driver since a long time. If you desire a 990controller not to be attached by the ncr53c8xx driver at Linux boot, you 991must use the 'excl' driver boot option. 992 99310.6 SCSI BUS checking boot option. 994 995When this option is set to a non-zero value, the driver checks SCSI lines 996logic state, 100 micro-seconds after having asserted the SCSI RESET line. 997The driver just reads SCSI lines and checks all lines read FALSE except RESET. 998Since SCSI devices shall release the BUS at most 800 nano-seconds after SCSI 999RESET has been asserted, any signal to TRUE may indicate a SCSI BUS problem. 1000Unfortunately, the following common SCSI BUS problems are not detected: 1001- Only 1 terminator installed. 1002- Misplaced terminators. 1003- Bad quality terminators. 1004On the other hand, either bad cabling, broken devices, not conformant 1005devices, ... may cause a SCSI signal to be wrong when te driver reads it. 1006 100710.7 IMMEDIATE ARBITRATION boot option 1008 1009This option is only supported by the SYM53C8XX driver (not by the NCR53C8XX). 1010 1011SYMBIOS 53C8XX chips are able to arbitrate for the SCSI BUS as soon as they 1012have detected an expected disconnection (BUS FREE PHASE). For this process 1013to be started, bit 1 of SCNTL1 IO register must be set when the chip is 1014connected to the SCSI BUS. 1015 1016When this feature has been enabled for the current connection, the chip has 1017every chance to win arbitration if only devices with lower priority are 1018competing for the SCSI BUS. By the way, when the chip is using SCSI id 7, 1019then it will for sure win the next SCSI BUS arbitration. 1020 1021Since, there is no way to know what devices are trying to arbitrate for the 1022BUS, using this feature can be extremely unfair. So, you are not advised 1023to enable it, or at most enable this feature for the case the chip lost 1024the previous arbitration (boot option 'iarb:1'). 1025 1026This feature has the following advantages: 1027 1028a) Allow the initiator with ID 7 to win arbitration when it wants so. 1029b) 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 1033Hmmm... But (a) may just prevent other devices from reselecting the initiator, 1034and delay data transfers or status/completions, and (b) may just waste 1035SCSI BUS bandwidth if the SCRIPTS execution lasts more than 4 micro-seconds. 1036 1037The use of IARB needs the SCSI_NCR_IARB_SUPPORT option to have been defined 1038at compile time and the 'iarb' boot option to have been set to a non zero 1039value at boot time. It is not that useful for real work, but can be used 1040to stress SCSI devices or for some applications that can gain advantage of 1041it. By the way, if you experience badnesses like 'unexpected disconnections', 1042'bad reselections', etc... when using IARB on heavy IO load, you should not 1043be surprised, because force-feeding anything and blocking its arse at the 1044same time cannot work for a long time. :-)) 1045 1046 104711. Some constants and flags of the ncr53c8xx.h header file 1048 1049Some of these are defined from the configuration parameters. To 1050change other "defines", you must edit the header file. Do that only 1051if you know what you are doing. 1052 1053SCSI_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 1064SCSI_NCR_IOMAPPED (default: not defined) 1065 If defined, normal I/O is forced. 1066 1067SCSI_NCR_SHARE_IRQ (default: defined) 1068 If defined, request shared IRQ. 1069 1070SCSI_NCR_MAX_TAGS (default: 8) 1071 Maximum number of simultaneous tagged commands to a device. 1072 Can be changed by "settags <target> <maxtags>" 1073 1074SCSI_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 1079SCSI_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 1083SCSI_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 1087SCSI_NCR_SETUP_DISCONNECTION (default: defined) 1088 If defined, targets are allowed to disconnect. 1089 1090SCSI_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 1094SCSI_NCR_SETUP_MASTER_PARITY (default: defined) 1095 If defined, master parity checking is enabled. 1096 1097SCSI_NCR_SETUP_SCSI_PARITY (default: defined) 1098 If defined, SCSI parity checking is enabled. 1099 1100SCSI_NCR_PROFILE_SUPPORT (default: not defined) 1101 If defined, profiling information is gathered. 1102 1103SCSI_NCR_MAX_SCATTER (default: 128) 1104 Scatter list size of the driver ccb. 1105 1106SCSI_NCR_MAX_TARGET (default: 16) 1107 Max number of targets per host. 1108 1109SCSI_NCR_MAX_HOST (default: 2) 1110 Max number of host controllers. 1111 1112SCSI_NCR_SETTLE_TIME (default: 2) 1113 Number of seconds the driver will wait after reset. 1114 1115SCSI_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 1120SCSI_NCR_CAN_QUEUE (default: 7*SCSI_NCR_MAX_TAGS) 1121 Max number of commands that can be queued to a host. 1122 1123SCSI_NCR_CMD_PER_LUN (default: SCSI_NCR_MAX_TAGS) 1124 Max number of commands queued to a host for a device. 1125 1126SCSI_NCR_SG_TABLESIZE (default: SCSI_NCR_MAX_SCATTER-1) 1127 Max size of the Linux scatter/gather list. 1128 1129SCSI_NCR_MAX_LUN (default: 8) 1130 Max number of LUNs per target. 1131 1132 113312. Installation 1134 1135This driver is part of the linux kernel distribution. 1136Driver files are located in the sub-directory "drivers/scsi" of the 1137kernel source tree. 1138 1139Driver files: 1140 1141 README.ncr53c8xx : this file 1142 ChangeLog.ncr53c8xx : change log 1143 ncr53c8xx.h : definitions 1144 ncr53c8xx.c : the driver code 1145 1146New driver versions are made available separately in order to allow testing 1147changes and new features prior to including them into the linux kernel 1148distribution. The following URL provides information on latest available 1149patches: 1150 1151 ftp://ftp.tux.org/pub/people/gerard-roudier/README 1152 1153 115413. Architecture dependent features. 1155 1156<Not yet written> 1157 1158 115914. Known problems 1160 116114.1 Tagged commands with Iomega Jaz device 1162 1163I have not tried this device, however it has been reported to me the 1164following: This device is capable of Tagged command queuing. However 1165while spinning up, it rejects Tagged commands. This behaviour is 1166conforms to 6.8.2 of SCSI-2 specifications. The current behaviour of 1167the driver in that situation is not satisfying. So do not enable 1168Tagged command queuing for devices that are able to spin down. The 1169other problem that may appear is timeouts. The only way to avoid 1170timeouts seems to edit linux/drivers/scsi/sd.c and to increase the 1171current timeout values. 1172 117314.2 Device names change when another controller is added. 1174 1175When you add a new NCR53C8XX chip based controller to a system that already 1176has one or more controllers of this family, it may happen that the order 1177the driver registers them to the kernel causes problems due to device 1178name changes. 1179When at least one controller uses NvRAM, SDMS BIOS version 4 allows you to 1180define the order the BIOS will scan the scsi boards. The driver attaches 1181controllers according to BIOS information if NvRAM detect option is set. 1182 1183If 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 119014.3 Using only 8 bit devices with a WIDE SCSI controller. 1191 1192When only 8 bit NARROW devices are connected to a 16 bit WIDE SCSI controller, 1193you must ensure that lines of the wide part of the SCSI BUS are pulled-up. 1194This can be achieved by ENABLING the WIDE TERMINATOR portion of the SCSI 1195controller card. 1196The TYAN 1365 documentation revision 1.2 is not correct about such settings. 1197(page 10, figure 3.3). 1198 119914.4 Possible data corruption during a Memory Write and Invalidate 1200 1201This problem is described in SYMBIOS DEL 397, Part Number 69-039241, ITEM 4. 1202 1203In some complex situations, 53C875 chips revision <= 3 may start a PCI 1204Write and Invalidate Command at a not cache-line-aligned 4 DWORDS boundary. 1205This is only possible when Cache Line Size is 8 DWORDS or greater. 1206Pentium systems use a 8 DWORDS cache line size and so are concerned by 1207this chip bug, unlike i486 systems that use a 4 DWORDS cache line size. 1208 1209When this situation occurs, the chip may complete the Write and Invalidate 1210command after having only filled part of the last cache line involved in 1211the transfer, leaving to data corruption the remainder of this cache line. 1212 1213Not using Write And Invalidate obviously gets rid of this chip bug, and so 1214it is now the default setting of the driver. 1215However, for people like me who want to enable this feature, I have added 1216part of a work-around suggested by SYMBIOS. This work-around resets the 1217addressing logic when the DATA IN phase is entered and so prevents the bug 1218from being triggered for the first SCSI MOVE of the phase. This work-around 1219should be enough according to the following: 1220 1221The only driver internal data structure that is greater than 8 DWORDS and 1222that is moved by the SCRIPTS processor is the 'CCB header' that contains 1223the context of the SCSI transfer. This data structure is aligned on 8 DWORDS 1224boundary (Pentium Cache Line Size), and so is immune to this chip bug, at 1225least on Pentium systems. 1226But the conditions of this bug can be met when a SCSI read command is 1227performed using a buffer that is 4 DWORDS but not cache-line aligned. 1228This cannot happen under Linux when scatter/gather lists are used since 1229they only refer to system buffers that are well aligned. So, a work around 1230may only be needed under Linux when a scatter/gather list is not used and 1231when the SCSI DATA IN phase is reentered after a phase mismatch. 1232 123315. SCSI problem troubleshooting 1234 123515.1 Problem tracking 1236 1237Most SCSI problems are due to a non conformant SCSI bus or to buggy 1238devices. If unfortunately you have SCSI problems, you can check the 1239following 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 1245If you do not find the source of problems, you can configure the 1246driver with no features enabled. 1247 1248- only asynchronous data transfers 1249- tagged commands disabled 1250- disconnections not allowed 1251 1252Now, if your SCSI bus is ok, your system have every chance to work 1253with this safe configuration but performances will not be optimal. 1254 1255If it still fails, then you can send your problem description to 1256appropriate mailing lists or news-groups. Send me a copy in order to 1257be sure I will receive it. Obviously, a bug in the driver code is 1258possible. 1259 1260 My email address: Gerard Roudier <groudier@free.fr> 1261 1262Allowing disconnections is important if you use several devices on 1263your SCSI bus but often causes problems with buggy devices. 1264Synchronous data transfers increases throughput of fast devices like 1265hard disks. Good SCSI hard disks with a large cache gain advantage of 1266tagged commands queuing. 1267 1268Try 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 1280Once you have found the device and the feature that cause problems, just 1281disable that feature for that device. 1282 128315.2 Understanding hardware error reports 1284 1285When the driver detects an unexpected error condition, it may display a 1286message of the following pattern. 1287 1288sym53c876-0:1: ERROR (0:48) (1-21-65) (f/95) @ (script 7c0:19000000). 1289sym53c876-0: script cmd = 19000000 1290sym53c876-0: regdump: da 10 80 95 47 0f 01 07 75 01 81 21 80 01 09 00. 1291 1292Some fields in such a message may help you understand the cause of the 1293problem, as follows: 1294 1295sym53c876-0:1: ERROR (0:48) (1-21-65) (f/95) @ (script 7c0:19000000). 1296............A.........B.C....D.E..F....G.H.......I.....J...K....... 1297 1298Field A : target number. 1299 SCSI ID of the device the controller was talking with at the moment the 1300 error occurs. 1301 1302Field 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 1315Field 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 1334For fields D,E,F,G and H, you may look into the sym53c8xx_defs.h file 1335that contains some minimal comments on IO register bits. 1336Field 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. 1339Field E : SBCL Scsi Bus Control Lines 1340 Actual value of control lines on the SCSI BUS. 1341Field F : SBDL Scsi Bus Data Lines 1342 Actual value of data lines on the SCSI BUS. 1343Field G : SXFER SCSI Transfer 1344 Contains the setting of the Synchronous Period for output and 1345 the current Synchronous offset (offset 0 means asynchronous). 1346Field H : SCNTL3 Scsi Control Register 3 1347 Contains the setting of timing values for both asynchronous and 1348 synchronous data transfers. 1349 1350Understanding Fields I, J, K and dumps requires to have good knowledge of 1351SCSI standards, chip cores functionnals and internal driver data structures. 1352You are not required to decode and understand them, unless you want to help 1353maintain the driver code. 1354 135516. Synchronous transfer negotiation tables 1356 1357Tables below have been created by calling the routine the driver uses 1358for synchronisation negotiation timing calculation and chip setting. 1359The first table corresponds to Ultra chips 53875 and 53C860 with 80 MHz 1360clock and 5 clock divisors. 1361The second one has been calculated by setting the scsi clock to 40 Mhz 1362and using 4 clock divisors and so applies to all NCR53C8XX chips in fast 1363SCSI-2 mode. 1364 1365Periods are in nano-seconds and speeds are in Mega-transfers per second. 13661 Mega-transfers/second means 1 MB/s with 8 bits SCSI and 2 MB/s with 1367Wide16 SCSI. 1368 136916.1 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 141716.2 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 145017. Serial NVRAM (added by Richard Waltham: dormouse@farsrobt.demon.co.uk) 1451 145217.1 Features 1453 1454Enabling serial NVRAM support enables detection of the serial NVRAM included 1455on Symbios and some Symbios compatible host adaptors, and Tekram boards. The 1456serial NVRAM is used by Symbios and Tekram to hold set up parameters for the 1457host adaptor and its attached drives. 1458 1459The Symbios NVRAM also holds data on the boot order of host adaptors in a 1460system with more than one host adaptor. This enables the order of scanning 1461the cards for drives to be changed from the default used during host adaptor 1462detection. 1463 1464This can be done to a limited extent at the moment using "reverse probe" but 1465this only changes the order of detection of different types of cards. The 1466NVRAM boot order settings can do this as well as change the order the same 1467types of cards are scanned in, something "reverse probe" cannot do. 1468 1469Tekram boards using Symbios chips, DC390W/F/U, which have NVRAM are detected 1470and this is used to distinguish between Symbios compatible and Tekram host 1471adaptors. This is used to disable the Symbios compatible "diff" setting 1472incorrectly set on Tekram boards if the CONFIG_SCSI_53C8XX_SYMBIOS_COMPAT 1473configuration parameter is set enabling both Symbios and Tekram boards to be 1474used together with the Symbios cards using all their features, including 1475"diff" support. ("led pin" support for Symbios compatible cards can remain 1476enabled when using Tekram cards. It does nothing useful for Tekram host 1477adaptors but does not cause problems either.) 1478 1479 148017.2 Symbios NVRAM layout 1481 1482typical data at NVRAM address 0x100 (53c810a NVRAM) 1483----------------------------------------------------------- 148400 00 148564 01 14868e 0b 1487 148800 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00 1489 149004 00 0f 00 00 10 00 50 00 00 01 00 00 62 149104 00 03 00 00 10 00 58 00 00 01 00 00 63 149204 00 01 00 00 10 00 48 00 00 01 00 00 61 149300 00 00 00 00 00 00 00 00 00 00 00 00 00 1494 14950f 00 08 08 64 00 0a 00 14960f 00 08 08 64 00 0a 00 14970f 00 08 08 64 00 0a 00 14980f 00 08 08 64 00 0a 00 14990f 00 08 08 64 00 0a 00 15000f 00 08 08 64 00 0a 00 15010f 00 08 08 64 00 0a 00 15020f 00 08 08 64 00 0a 00 1503 15040f 00 08 08 64 00 0a 00 15050f 00 08 08 64 00 0a 00 15060f 00 08 08 64 00 0a 00 15070f 00 08 08 64 00 0a 00 15080f 00 08 08 64 00 0a 00 15090f 00 08 08 64 00 0a 00 15100f 00 08 08 64 00 0a 00 15110f 00 08 08 64 00 0a 00 1512 151300 00 00 00 00 00 00 00 151400 00 00 00 00 00 00 00 151500 00 00 00 00 00 00 00 151600 00 00 00 00 00 00 00 151700 00 00 00 00 00 00 00 151800 00 00 00 00 00 00 00 151900 00 00 00 00 00 00 00 152000 00 00 00 00 00 00 00 1521 152200 00 00 00 00 00 00 00 152300 00 00 00 00 00 00 00 152400 00 00 00 00 00 00 00 152500 00 00 00 00 00 00 00 152600 00 00 00 00 00 00 00 152700 00 00 00 00 00 00 00 152800 00 00 00 00 00 00 00 152900 00 00 00 00 00 00 00 1530 153100 00 00 00 00 00 00 00 153200 00 00 00 00 00 00 00 153300 00 00 00 00 00 00 00 1534 1535fe fe 153600 00 153700 00 1538----------------------------------------------------------- 1539NVRAM layout details 1540 1541NVRAM Address 0x000-0x0ff not used 1542 0x100-0x26f initialised data 1543 0x270-0x7ff not used 1544 1545general 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 1553data 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----------------------------------------------------------- 1563header 1564 156500 00 - ?? start marker 156664 01 - byte count (lsb/msb excludes header/trailer) 15678e 0b - checksum (lsb/msb excludes header/trailer) 1568----------------------------------------------------------- 1569controller set up 1570 157100 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 1588remaining bytes unknown - they do not appear to change in my 1589current set up for any of the controllers. 1590 1591default set up is identical for 53c810a and 53c875 NVRAM 1592(Removable Media added Symbios BIOS version 4.09) 1593----------------------------------------------------------- 1594boot configuration 1595 1596boot order set by order of the devices in this table 1597 159804 00 0f 00 00 10 00 50 00 00 01 00 00 62 -- 1st controller 159904 00 03 00 00 10 00 58 00 00 01 00 00 63 2nd controller 160004 00 01 00 00 10 00 48 00 00 01 00 00 61 3rd controller 160100 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 1611remaining bytes unknown - they do not appear to change in my 1612current set up 1613 1614default set up is identical for 53c810a and 53c875 NVRAM 1615----------------------------------------------------------- 1616device set up (up to 16 devices - includes controller) 1617 16180f 00 08 08 64 00 0a 00 - id 0 16190f 00 08 08 64 00 0a 00 16200f 00 08 08 64 00 0a 00 16210f 00 08 08 64 00 0a 00 16220f 00 08 08 64 00 0a 00 16230f 00 08 08 64 00 0a 00 16240f 00 08 08 64 00 0a 00 16250f 00 08 08 64 00 0a 00 1626 16270f 00 08 08 64 00 0a 00 16280f 00 08 08 64 00 0a 00 16290f 00 08 08 64 00 0a 00 16300f 00 08 08 64 00 0a 00 16310f 00 08 08 64 00 0a 00 16320f 00 08 08 64 00 0a 00 16330f 00 08 08 64 00 0a 00 16340f 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 1652remaining bytes unknown - they do not appear to change in my 1653current set up 1654 1655?? use of this data is a guess but seems reasonable 1656(but it could be max bus width) 1657 1658default set up for 53c810a NVRAM 1659default 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 166500 00 00 00 00 00 00 00 (19x8bytes) 1666. 1667. 166800 00 00 00 00 00 00 00 1669 1670default set up is identical for 53c810a and 53c875 NVRAM 1671----------------------------------------------------------- 1672trailer 1673 1674fe fe - ? end marker ? 167500 00 167600 00 1677 1678default set up is identical for 53c810a and 53c875 NVRAM 1679----------------------------------------------------------- 1680 1681 1682 168317.3 Tekram NVRAM layout 1684 1685nvram 64x16 (1024 bit) 1686 1687Drive settings 1688 1689Drive 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 1726Global settings 1727 1728Host 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 1756Host 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 1774Host 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 1781checksum (addr 0x111111) 1782 1783checksum = 0x1234 - (sum addr 0-63) 1784 1785---------------------------------------------------------------------------- 1786 1787default nvram data: 1788 17890x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 17900x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 17910x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 17920x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 1793 17940x0f07 0x0400 0x0001 0x0000 0x0000 0x0000 0x0000 0x0000 17950x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 17960x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 17970x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0xfbbc 1798 1799 180018. Support for Big Endian 1801 1802The PCI local bus has been primarily designed for x86 architecture. 1803As a consequence, PCI devices generally expect DWORDS using little endian 1804byte ordering. 1805 180618.1 Big Endian CPU 1807 1808In order to support NCR chips on a Big Endian architecture the driver has to 1809perform byte reordering each time it is needed. This feature has been 1810added to the driver by Cort <cort@cs.nmt.edu> and is available in driver 1811version 2.5 and later ones. For the moment Big Endian support has only 1812been tested on Linux/PPC (PowerPC). 1813 181418.2 NCR chip in Big Endian mode of operations 1815 1816It can be read in SYMBIOS documentation that some chips support a special 1817Big Endian mode, on paper: 53C815, 53C825A, 53C875, 53C875N, 53C895. 1818This mode of operations is not software-selectable, but needs pin named 1819BigLit to be pulled-up. Using this mode, most of byte reorderings should 1820be avoided when the driver is running on a Big Endian CPU. 1821Driver version 2.5 is also, in theory, ready for this feature. 1822 1823=============================================================================== 1824End of NCR53C8XX driver README file 1825