patch-2.2.18 linux/drivers/scsi/README.ncr53c8xx
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- Lines: 636
- Date:
Thu Aug 31 14:50:52 2000
- Orig file:
v2.2.17/drivers/scsi/README.ncr53c8xx
- Orig date:
Fri Apr 21 12:46:31 2000
diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/drivers/scsi/README.ncr53c8xx linux/drivers/scsi/README.ncr53c8xx
@@ -1,10 +1,10 @@
-The Linux NCR53C8XX driver README file
+The Linux NCR53C8XX/SYM53C8XX drivers README file
Written by Gerard Roudier <groudier@club-internet.fr>
21 Rue Carnot
95170 DEUIL LA BARRE - FRANCE
-9 May 1999
+29 May 1999
===============================================================================
1. Introduction
@@ -25,14 +25,39 @@
8.6 Clear profile counters
8.7 Set flag (no_disc)
8.8 Set verbose level
+ 8.9 Reset all logical units of a target
+ 8.10 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 Master parity checking
+ 10.2.2 Scsi parity checking
+ 10.2.3 Scsi disconnections
+ 10.2.4 Special features
+ 10.2.5 Ultra SCSI support
+ 10.2.6 Default number of tagged commands
+ 10.2.7 Default synchronous period factor
+ 10.2.8 Negotiate synchronous with all devices
+ 10.2.9 Verbosity level
+ 10.2.10 Debug mode
+ 10.2.11 Burst max
+ 10.2.12 LED support
+ 10.2.13 Max wide
+ 10.2.14 Differential mode
+ 10.2.15 IRQ mode
+ 10.2.16 Reverse probe
+ 10.2.17 Fix up PCI configuration space
+ 10.2.18 Serial NVRAM
+ 10.2.19 Check SCSI BUS
+ 10.2.20 Exclude a host from being attached
+ 10.2.21 Suggest a default SCSI id for hosts
+ 10.2.22 Enable use of IMMEDIATE ARBITRATION
10.3 Advised boot setup commands
10.4 PCI configuration fix-up boot option
10.5 Serial NVRAM support boot option
10.6 SCSI BUS checking boot option
+ 10.7 IMMEDIATE ARBITRATION boot option
11. Some constants and flags of the ncr53c8xx.h header file
12. Installation
13. Architecture dependent features
@@ -43,6 +68,8 @@
14.4 Possible data corruption during a Memory Write and Invalidate
14.5 IRQ sharing problems
15. SCSI problem troubleshooting
+ 15.1 Problem tracking
+ 15.2 Understanding hardware error reports
16. Synchonous transfer negotiation tables
16.1 Synchronous timings for 53C875 and 53C860 Ultra-SCSI controllers
16.2 Synchronous timings for fast SCSI-2 53C8XX controllers
@@ -69,11 +96,12 @@
It is now available as a bundle of 2 drivers:
- ncr53c8xx generic driver that supports all the SYM53C8XX family including
- the ealiest 810 rev. 1 and the latest 896 2 channels LVD SCSI controller.
+ the ealiest 810 rev. 1, the latest 896 (2 channel LVD SCSI controller) and
+ the new 895A (1 channel LVD SCSI controller).
- sym53c8xx enhanced driver (a.k.a. 896 drivers) that drops support of oldest
chips in order to gain advantage of new features, as LOAD/STORE intructions
available since the 810A and hardware phase mismatch available with the
- latest 896.
+ 896 and the 895A.
You can find technical information about the NCR 8xx family in the
PCI-HOWTO written by Michael Will and in the SCSI-HOWTO written by
@@ -95,15 +123,17 @@
These tools are not ALPHA but quite clean and work quite well.
It is essential you have the 'scsiinfo' package.
-This short documentation only describes the features of the NCR53C8XX
-driver, configuration parameters and control commands available
-through the proc SCSI file system read / write operations.
+This short documentation describes the features of the generic and enhanced
+drivers, configuration parameters and control commands available through
+the proc SCSI file system read / write operations.
This driver has been tested OK with linux/i386, Linux/Alpha and Linux/PPC.
Latest driver version and patches are available at:
ftp://ftp.tux.org/pub/people/gerard-roudier
+or
+ ftp://ftp.symbios.com/mirror/ftp.tux.org/pub/tux/roudier/drivers
I am not a native speaker of English and there are probably lots of
mistakes in this README file. Any help will be welcome.
@@ -136,7 +166,14 @@
875 Y Y FAST20 40 MB/s Y Y
876 Y Y FAST20 40 MB/s Y Y
895 Y Y FAST40 80 MB/s Y Y
+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 N Y
+1010_66* Y Y FAST80 160 MB/s N Y
+
+* Chip supports 33MHz and 66MHz PCI buses.
Summary of other supported features:
@@ -156,21 +193,25 @@
3.1 Optimized SCSI SCRIPTS.
-The 810A, 825A, 875, 895 and newest 896 support new SCSI SCRIPTS instructions
-named LOAD and STORE that allow to move 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.
+The 810A, 825A, 875, 895, 896 and 895A 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.
3.2 New features of the SYM53C896 (64 bit PCI dual LVD SCSI controller)
-The 896 allows to handle the phase mismatch context saving from SCRIPTS
-(avoids the phase mismatch interrupt that stops the SCSI processor
+The 896 and the 895A 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).
Implementing this without using LOAD/STORE instructions would be painfull
-and I did'nt even try it. This chip also supports 64 bit PCI transactions
-and addressing. The SCRIPTS processor is not true 64 bit, but uses segment
+and I did'nt even want to try it.
+
+The 896 chip supports 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.
@@ -219,9 +260,13 @@
is currently set to 8 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.
-The driver supports up to 64 commands per device, but using more than
-32 is generally not worth it, unless you are using a very large disk
-or disk array.
+
+The sym53c8xx driver supports up to 255 commands per device, and the
+generic ncr53c8xx driver supports up to 64, but using more than 32 is
+generally not worth-while, unless you are using a very large disk or disk
+array. 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
@@ -491,6 +536,24 @@
The driver default verbose level is 1. This command allows to change
th driver verbose level after boot-up.
+8.9 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.
+ (Only supported by the SYM53C8XX driver and provided for test purpose)
+
+8.10 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.
+ (Only supported by the SYM53C8XX driver and provided for test purpose)
+
+
9. Configuration parameters
If the firmware of all your devices is perfect enough, all the
@@ -566,10 +629,11 @@
Setup commands can be passed to the driver either at boot time or as a
string variable using 'insmod'.
-A boot setup command for the ncr53c8xx driver begins with the driver name
-"ncr53c8xx=". The kernel syntax parser then expects an optionnal list of
-integers separated with comma followed by an optionnal list of comma-
-separated strings. Example of boot setup command under lilo prompt:
+A boot setup command for the ncr53c8xx (sym53c8xx) driver begins with the
+driver name "ncr53c8xx="(sym53c8xx). The kernel syntax parser then expects
+an optionnal list of integers separated with comma followed by an optional
+list of comma-separated strings. Example of boot setup command under lilo
+prompt:
lilo: linux root=/dev/hda2 ncr53c8xx=tags:4,sync:10,debug:0x200
@@ -582,7 +646,7 @@
The following command will install driver module with the same options as
above.
-insmod ncr53c8xx.o ncr53c8xx="tags:4 sync:10 debug:0x200"
+ insmod ncr53c8xx.o ncr53c8xx="tags:4 sync:10 debug:0x200"
For the moment, the integer list of arguments is discarded by the driver.
It will be used in the future in order to allow a per controller setup.
@@ -590,40 +654,54 @@
Each string argument must be specified as "keyword:value". Only lower-case
characters and digits are allowed.
+In a system that contains multiple 53C8xx adapters insmod will install the
+specified driver on each adapter. To exclude a chip use the 'excl' keyword.
+
+The sequence of commands,
+
+ insmod sym53c8xx sym53c8xx=excl:0x1400
+ insmod ncr53c8xx
+
+installs the sym53c8xx driver on all adapters except the one at IO port
+address 0x1400 and then installs the ncr53c8xx driver to the adapter at IO
+port address 0x1400.
+
+
10.2 Available arguments
-Master parity checking
- mpar:y enabled
- mpar:n disabled
-
-Scsi parity checking
- spar:y enabled
- spar:n disabled
-
-Scsi disconnections
- disc:y enabled
- disc:n disabled
+10.2.1 Master parity checking
+ mpar:y enabled
+ mpar:n disabled
+
+10.2.2 Scsi parity checking
+ spar:y enabled
+ spar:n disabled
+
+10.2.3 Scsi disconnections
+ disc:y enabled
+ disc:n disabled
-Special features
+10.2.4 Special features
Only apply to 810A, 825A, 860, 875 and 895 controllers.
Have no effect with other ones.
- specf:y (or 1) enabled
- specf:n (or 0) disabled
- specf:3 enabled except Memory Write And Invalidate
+ specf:y (or 1) enabled
+ specf:n (or 0) disabled
+ specf:3 enabled except Memory Write And Invalidate
The default driver setup is 'specf:3'. As a consequence, option 'specf:y'
must be specified in the boot setup command to enable Memory Write And
Invalidate.
-Ultra SCSI support
- Only apply to 860, 875 and 895 controllers.
+10.2.5 Ultra SCSI support
+ Only apply to 860, 875, 895, 895a, 896, 1010 and 1010_66 controllers.
Have no effect with other ones.
- ultra:2 Ultra2 enabled
- ultra:1 Ultra enabled
- ultra:n disabled
-
-Default number of tagged commands
- tags:0 (or tags:1 ) tagged command queuing disabled
- tags:#tags (#tags > 1) tagged command queuing enabled
+ ultra:n All ultra speeds enabled
+ ultra:2 Ultra2 enabled
+ ultra:1 Ultra enabled
+ ultra:0 Ultra speeds disabled
+
+10.2.6 Default number of tagged commands
+ tags:0 (or tags:1 ) tagged command queuing disabled
+ tags:#tags (#tags > 1) tagged command queuing enabled
#tags will be truncated to the max queued commands configuration parameter.
This option also allows to specify a command queue depth for each device
that support tagged command queueing.
@@ -635,9 +713,9 @@
- controller #1 target #1 logical unit #2 -> 32 commands,
- all other logical units (all targets, all controllers) -> 10 commands.
-Default synchronous period factor
- sync:255 disabled (asynchronous transfer mode)
- sync:#factor
+10.2.7 Default synchronous period factor
+ sync:255 disabled (asynchronous transfer mode)
+ sync:#factor
#factor = 10 Ultra-2 SCSI 40 Mega-transfers / second
#factor = 11 Ultra-2 SCSI 33 Mega-transfers / second
#factor < 25 Ultra SCSI 20 Mega-transfers / second
@@ -646,19 +724,19 @@
In all cases, the driver will use the minimum transfer period supported by
controllers according to NCR53C8XX chip type.
-Negotiate synchronous with all devices
- (force sync nego)
- fsn:y enabled
- fsn:n disabled
-
-Verbosity level
- verb:0 minimal
- verb:1 normal
- verb:2 too much
-
-Debug mode
- debug:0 clear debug flags
- debug:#x set debug flags
+10.2.8 Negotiate synchronous with all devices
+ (force sync nego)
+ fsn:y enabled
+ fsn:n disabled
+
+10.2.9 Verbosity level
+ verb:0 minimal
+ verb:1 normal
+ verb:2 too much
+
+10.2.10 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
@@ -677,10 +755,10 @@
You can play safely with DEBUG_NEGO. However, some of these flags may
generate bunches of syslog messages.
-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)
+10.2.11 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.
The NCR53C875 and NCR53C825A support up to 128 burst transfers (#x = 7).
Other chips only support up to 16 (#x = 4).
@@ -688,42 +766,42 @@
and revision ids. By default the driver uses the maximum value supported
by the chip.
-LED support
- led:1 enable LED support
- led:0 disable LED support
+10.2.12 LED support
+ led:1 enable LED support
+ led:0 disable LED support
Donnot enable LED support if your scsi board does not use SDMS BIOS.
(See 'Configuration parameters')
-Max wide
- wide:1 wide scsi enabled
- wide:0 wide scsi disabled
+10.2.13 Max wide
+ wide:1 wide scsi enabled
+ wide:0 wide scsi disabled
Some scsi boards use a 875 (ultra wide) and only supply narrow connectors.
If you have connected a wide device with a 50 pins to 68 pins cable
converter, any accepted wide negotiation will break further data transfers.
In such a case, using "wide:0" in the bootup command will be helpfull.
-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
-
-IRQ mode
- irqm:0 always open drain
- irqm:1 same as initial settings (assumed BIOS settings)
- irqm:2 always totem pole
- irqm:0x10 driver will not use SA_SHIRQ flag when requesting irq
- irqm:0x20 driver will not use SA_INTERRUPT flag when requesting irq
+10.2.14 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
+
+10.2.15 IRQ mode
+ irqm:0 always open drain
+ irqm:1 same as initial settings (assumed BIOS settings)
+ irqm:2 always totem pole
+ irqm:0x10 driver will not use SA_SHIRQ flag when requesting irq
+ irqm:0x20 driver will not use SA_INTERRUPT flag when requesting irq
(Bits 0x10 and 0x20 can be combined with hardware irq mode option)
-Reverse probe
- revprob:n probe chip ids from the PCI configuration in this order:
- 810, 815, 820, 860, 875, 885, 895, 896
- revprob:y probe chip ids in the reverse order.
+10.2.16 Reverse probe
+ revprob:n probe chip ids from the PCI configuration in this order:
+ 810, 815, 820, 860, 875, 885, 895, 896
+ revprob:y probe chip ids in the reverse order.
-Fix up PCI configuration space
- pcifix:<option bits>
+10.2.17 Fix up PCI configuration space
+ pcifix:<option bits>
Available option bits:
0x0: No attempt to fix PCI configuration space registers values.
@@ -733,35 +811,36 @@
Use 'pcifix:7' in order to allow the driver to fix up all PCI features.
-Serial NVRAM
- nvram:n do not look for serial NVRAM
- nvram:y test controllers for onboard serial NVRAM
- (alternate binary form)
- mvram=<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)
+10.2.18 Serial NVRAM
+ nvram:n do not look for serial NVRAM
+ nvram:y test controllers for onboard serial NVRAM
+ (alternate binary form)
+ mvram=<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)
-Check SCSI BUS
- buschk:<option bits>
+10.2.19 Check SCSI BUS
+ buschk:<option bits>
Available option bits:
0x0: No check.
0x1: Check and donnot attach the controller on error.
0x2: Check and just warn on error.
+ 0x4: Disable SCSI bus integrity checking.
-Exclude a host from being attached
- excl=<io_address>
+10.2.20 Exclude a host from being attached
+ excl=<io_address>
Prevent host at a given io address from being attached.
- For example 'ncr53c8xx=excl:0xb400,excl:0xc000' indicates to the
+ For example 'ncr53c8xx=excl:0xb400,excl:0xc000' indicate to the
ncr53c8xx driver not to attach hosts at address 0xb400 and 0xc000.
-Suggest a default SCSI id for hosts
- hostid:255 no id suggested.
- hostid:#x (0 < x < 7) x suggested for hosts SCSI id.
+10.2.21 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
@@ -769,6 +848,16 @@
try to deduce the value previously set in the hardware and use value
7 if the hardware value is zero.
+10.2.22 Enable use of IMMEDIATE ARBITRATION
+ (only supported by the sym53c8xx driver. See 10.7 for more details)
+ iarb:0 donnot use this feature.
+ iarb:#x use this feature according to bit fields as follow:
+
+ bit 0 (1) : enable IARB each time the initiator has been reselected
+ when it arbitrated for the SCSI BUS.
+ (#x >> 4) : maximum number of successive settings of IARB if the initiator
+ win arbitration and it has other commands to send to a device.
+
Boot fail safe
safe:y load the following assumed fail safe initial setup
@@ -792,6 +881,7 @@
differential support from BIOS settings diff:1
irq mode from BIOS settings irqm:1
SCSI BUS check donnot attach on error buschk:1
+ immediate arbitration disabled iarb:0
10.3 Advised boot setup commands
@@ -920,6 +1010,45 @@
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.
+10.7 IMMEDIATE ARBITRATION boot option
+
+This option is only supported by the SYM53C8XX driver (not by the NCR53C8XX).
+
+SYMBIOS 53C8XX chips are able to arbitrate for the SCSI BUS as soon as they
+have detected an expected disconnection (BUS FREE PHASE). For this process
+to be started, bit 1 of SCNTL1 IO register must be set when the chip is
+connected to the SCSI BUS.
+
+When this feature has been enabled for the current connection, the chip has
+every chance to win arbitration if only devices with lower priority are
+competing for the SCSI BUS. By the way, when the chip is using SCSI id 7,
+then it will for sure win the next SCSI BUS arbitration.
+
+Since, there is no way to know what devices are trying to arbitrate for the
+BUS, using this feature can be extremally unfair. So, you are not advised
+to enable it, or at most enable this feature for the case the chip lost
+the previous arbitration (boot option 'iarb:1').
+
+This feature has the following advantages:
+
+a) Allow the initiator with ID 7 to win arbitration when it wants so.
+b) Overlap at least 4 micro-seconds of arbitration time with the execution
+ of SCRIPTS that deal with the end of the current connection and that
+ starts the next job.
+
+Hmmm... But (a) may just prevent other devices from reselecting the initiator,
+and delay data transfers or status/completions, and (b) may just waste
+SCSI BUS bandwidth if the SCRIPTS execution lasts more than 4 micro-seconds.
+
+The use of IARB needs the SCSI_NCR_IARB_SUPPORT option to have been defined
+at compile time and the 'iarb' boot option to have been set to a non zero
+value at boot time. It is not that usefull for real work, but can be used
+to stress SCSI devices or for some applications that can gain advantage of
+it. By the way, if you experience badnesses like 'unexpected disconnections',
+'bad reselections', etc... when using IARB on heavy IO load, you should not
+be surprised, because force-feeding anything and blocking its arse at the
+same time cannot work for a long time. :-))
+
11. Some constants and flags of the ncr53c8xx.h header file
@@ -1133,6 +1262,8 @@
15. SCSI problem troubleshooting
+15.1 Problem tracking
+
Most SCSI problems are due to a non conformant SCSI bus or to buggy
devices. If infortunately you have SCSI problems, you can check the
following things:
@@ -1179,6 +1310,77 @@
Once you have found the device and the feature that cause problems, just
disable that feature for that device.
+15.2 Understanding hardware error reports
+
+When the driver detects an unexpected error condition, it may display a
+message of the following pattern.
+
+sym53c876-0:1: ERROR (0:48) (1-21-65) (f/95) @ (script 7c0:19000000).
+sym53c876-0: script cmd = 19000000
+sym53c876-0: 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:
+
+sym53c876-0:1: ERROR (0:48) (1-21-65) (f/95) @ (script 7c0:19000000).
+............A.........B.C....D.E..F....G.H.......I.....J...K.......
+
+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 functionning
+ properly.
+ Bit 0x04 : UDC Undexpected 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 occured.
+ Bit 0x02 : RST SCSI BUS Reset
+ Generally SCSI targets donnot 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.
+
+Understanding Fields I, J, K 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.
16. Synchonous transfer negotiation tables
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)