The Linux NCR53C8XX driver README file
Written by Gerard Roudier <groudier@club-internet.fr>
21 Rue Carnot
95170 DEUIL LA BARRE - FRANCE
19 June 1997
===============================================================================
1. Introduction
2. Supported chips and SCSI features
3. Summary of other supported features
4. Memory mapped I/O versus normal I/O
5. Tagged command queueing
6. Parity checking
7. Profiling information
8. Control commands
8.1 Set minimum synchronous period
8.2 Set wide size
8.3 Set maximum number of concurrent tagged commands
8.4 Set order type for tagged command
8.5 Set debug mode
8.6 Clear profile counters
8.7 Set flag (no_sync)
8.8 Debug error recovery
9. Configuration parameters
10. Boot setup commands
10.1 Syntax
10.2 Available arguments
10.3 Advised boot setup commands
10.4 PCI configuration fix-up boot option
10.5 Serial NVRAM support boot option
11. Some constants and flags of the ncr53c8xx.h header file
12. Installation
12.1 Provided files
12.2 Installation procedure
13. Control commands under linux-1.2.13
14. Known problems
14.1 Tagged commands with Iomega Jaz device
14.2 Device names change when another controller is added
15. SCSI problem troubleshooting
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
17. Serial NVRAM support (by Richard Waltham)
17.1 Features
17.2 Symbios NVRAM layout
17.3 Tekram NVRAM layout
===============================================================================
1. Introduction
This driver has been ported from FreeBSD to Linux and is currently
maintained by:
Gerard Roudier <groudier@club-internet.fr>
The original driver has been written for 386bsd and FreeBSD by:
Wolfgang Stanglmeier <wolf@cologne.de>
Stefan Esser <se@mi.Uni-Koeln.de>
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
Drew Eckhardt.
Information about new chips is available at SYMBIOS web server:
http://www.symbios.com/
SCSI standard documentations are available at SYMBIOS ftp server:
ftp://ftp.symbios.com/
Usefull SCSI tools written by Eric Youngdale are available at tsx-11:
ftp://tsx-11.mit.edu/pub/linux/ALPHA/scsi/scsiinfo-X.Y.tar.gz
ftp://tsx-11.mit.edu/pub/linux/ALPHA/scsi/scsidev-X.Y.tar.gz
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 driver has been tested OK with linux/i386 and Linux/Alpha.
Latest driver version and patches are available at:
ftp://linux.wauug.org/pub/roudier
I am not a native speaker of English and there are probably lots of
mistakes in this README file. Any help will be welcome.
2. Supported chips and SCSI features
The following features are supported for all chips:
Synchronous negotiation
Disconnection
Tagged command queuing
SCSI parity checking
Master parity checking
"Wide negotiation" is supported for chips that allow it. The
following table shows some characteristics of NCR 8xx family chips:
On board Supported by Tested with
Chip SDMS BIOS Wide Ultra SCSI the driver the driver
---- --------- ---- ---------- ------------ -----------
810 N N N Y Y
810A N N N Y Y
815 Y N N Y Y
825 Y Y N Y Y
825A Y Y N Y Y
860 N N Y Y Y
875 Y Y Y Y Y
895 Y Y Y(1) Y not yet
(1) The 895 chip is supported 'on paper'.
3. Summary of other supported features.
Module: allow to load the driver
Memory mapped I/O: increases performance
Profiling information: read operations from the proc SCSI file system
Control commands: write operations to the proc SCSI file system
Debugging information: written to syslog (expert only)
Scatter / gather
Shared interrupt
Boot setup commands
Serial NVRAM: Symbios and Tekram formats
4. Memory mapped I/O versus normal I/O
Memory mapped I/O has less latency than normal I/O. Since
linux-1.3.x, memory mapped I/O is used rather than normal I/O. Memory
mapped I/O seems to work fine on most hardware configurations, but
some poorly designed motherboards may break this feature.
The configuration option CONFIG_SCSI_NCR53C8XX_IOMAPPED forces the
driver to use normal I/O in all cases.
5. Tagged command queueing
Some SCSI devices do not properly support tagged command queuing. A
safe configuration is to not enable tagged command queuing support at
boot-up, and to enable support of it with the control command
"settags" described further in this text.
Once you are sure that all your devices properly support tagged
command queuing, you can enable it by default with the
CONFIG_SCSI_NCR53C8XX_TAGGED_QUEUE configuration option.
The maximum number of simultaneous tagged commands queued to a device
is currently set to 4 by default. It is defined in the file
ncr53c8xx.h by SCSI_NCR_MAX_TAGS. This value is suitable for most SCSI
disks. With large SCSI disks (> 2GB, cache > 512KB average seek time
< 10 ms), 8 tagged commands may give better performance.
In some special conditions, some SCSI disk firmwares may return a
QUEUE FULL status for a SCSI command. This behaviour is managed by the
driver by the following heuristic:
- Each time a QUEUE FULL status is returned, tagged command queueing is
temporarily disabled.
- Every 100 successfully completed SCSI commands, if allowed by the
current limit, the maximum number of queueable commands is
incremented and tagged command queueing is reenabled.
6. Parity checking
The driver supports SCSI parity checking and PCI bus master parity
checking. These features must be enabled in order to ensure safe data
transfers. However, some flawed devices or mother boards will have
problems with parity. You can disable parity by choosing first
"CONFIG_EXPERIMENTAL". Then, "make config" will allow to set the
following configuration options:
CONFIG_SCSI_NCR53C8XX_DISABLE_PARITY_CHECK (disable SCSI parity checking)
CONFIG_SCSI_NCR53C8XX_DISABLE_MPARITY_CHECK (disable master parity checking)
7. Profiling information
Profiling information is available through the proc SCSI file system.
The device associated with a host has the following pathname:
/proc/scsi/ncr53c8xx/N (N=0,1,2 ....)
Generally, only 1 board is used on hardware configuration, and that device is:
/proc/scsi/ncr53c8xx/0
However, if the driver has been made as module, the number of the
hosts is incremented each time the driver is loaded.
In order to display profiling information, just enter:
cat /proc/scsi/ncr53c8xx/0
and you will get something like the following text:
-------------------------------------------------------
General information:
Chip NCR53C810, device id 0x1, revision id 0x2
IO port address 0x6000, IRQ number 10
Using memory mapped IO at virtual address 0x282c000
Synchronous transfer period 25, max commands per lun 4
Profiling information:
num_trans = 18014
num_kbytes = 671314
num_disc = 25763
num_break = 1673
num_int = 1685
num_fly = 18038
ms_setup = 4940
ms_data = 369940
ms_disc = 183090
ms_post = 1320
-------------------------------------------------------
General information is easy to understand. The device ID and the
revision ID identify the SCSI chip as follows:
Chip Device id Revision Id
---- --------- -----------
810 0x1 < 0x10
810A 0x1 >= 0x10
815 0x4
825 0x3 < 0x10
860 0x6
825A 0x3 >= 0x10
875 0xf
895 0xc
The profiling information is updated upon completion of SCSI commands.
A data structure is allocated and zeroed when the host adapter is
attached. So, if the driver is a module, the profile counters are
cleared each time the driver is loaded. The "clearprof" command
allows you to clear these counters at any time.
The following counters are available:
("num" prefix means "number of",
"ms" means milli-seconds)
num_trans
Number of completed commands
Example above: 18014 completed commands
num_kbytes
Number of kbytes transferred
Example above: 671 MB transferred
num_disc
Number of SCSI disconnections
Example above: 25763 SCSI disconnections
num_break
number of script interruptions (phase mismatch)
Example above: 1673 script interruptions
num_int
Number of interrupts other than "on the fly"
Example above: 1685 interruptions not "on the fly"
num_fly
Number of interrupts "on the fly"
Example above: 18038 interruptions "on the fly"
ms_setup
Elapsed time for SCSI commands setups
Example above: 4.94 seconds
ms_data
Elapsed time for data transfers
Example above: 369.94 seconds spent for data transfer
ms_disc
Elapsed time for SCSI disconnections
Example above: 183.09 seconds spent disconnected
ms_post
Elapsed time for command post processing
(time from SCSI status get to command completion call)
Example above: 1.32 seconds spent for post processing
Due to the 1/100 second tick of the system clock, "ms_post" time may
be wrong.
In the example above, we got 18038 interrupts "on the fly" and only
1673 script breaks generally due to disconnections inside a segment
of the scatter list.
8. Control commands
Control commands can be sent to the driver with write operations to
the proc SCSI file system. The generic command syntax is the
following:
echo "<verb> <parameters>" >/proc/scsi/ncr53c8xx/0
(assumes controller number is 0)
Using "all" for "<target>" parameter with the commands below will
apply to all targets of the SCSI chain (except the controller).
Available commands:
8.1 Set minimum synchronous period factor
setsync <target> <period factor>
target: target number
period: minimum synchronous period.
Maximum speed = 1000/(4*period factor) except for special
cases below.
Specify a period of 255, to force asynchronous transfer mode.
10 means 25 nano-seconds synchronous period
11 means 30 nano-seconds synchronous period
12 means 50 nano-seconds synchronous period
8.2 Set wide size
setwide <target> <size>
target: target number
size: 0=8 bits, 1=16bits
8.3 Set maximum number of concurrent tagged commands
settags <target> <tags>
target: target number
tags: number of concurrent tagged commands
must not be greater than SCSI_NCR_MAX_TAGS (default: 4)
8.4 Set order type for tagged command
setorder <order>
order: 3 possible values:
simple: use SIMPLE TAG for all operations (read and write)
ordered: use ORDERED TAG for all operations
default: use default tag type,
SIMPLE TAG for read operations
ORDERED TAG for write operations
8.5 Set debug mode
setdebug <list of debug flags>
Available debug flags:
alloc: print info about memory allocations (ccb, lcb)
queue: print info about insertions into the command start queue
result: print sense data on CHECK CONDITION status
scatter: print info about the scatter process
scripts: print info about the script binding process
tiny: print minimal debugging information
timing: print timing information of the NCR chip
nego: print information about SCSI negotiations
phase: print information on script interruptions
Use "setdebug" with no argument to reset debug flags.
8.6 Clear profile counters
clearprof
The profile counters are automatically cleared when the amount of
data transfered reaches 1000 GB in order to avoid overflow.
The "clearprof" command allows you to clear these counters at any time.
8.7 Set flag (no_sync)
setflag <target> <flag>
target: target number
For the moment, only one flag is available:
no_sync: not allow target to disconnect.
Do not specify any flag in order to reset the flag. For example:
- setflag 4
will reset no_sync flag for target 4, so will allow it disconnections.
- setflag all
will allow disconnection for all devices on the SCSI bus.
8.8 Debug error recovery
debug_error_recovery <error to trigger>
Available error type to trigger:
sge: SCSI gross error
abort: abort command from the middle-level driver
reset: reset command from the middle-level driver
parity: scsi parity detected in DATA IN phase
none: restore driver normal behaviour
The code corresponding to this feature is normally not compiled.
Its purpose is driver testing only. In order to compile the code
that allows to trigger error recovery you must define at compile time
SCSI_NCR_DEBUG_ERROR_RECOVERY.
If you have compiled the driver with this option, nothing will happen
as long as you donnot use the control command 'debug_error_recovery'
with sge, abort, reset or parity as argument.
If you select an error type, it will be triggered by the driver every
30 seconds.
9. Configuration parameters
If the firmware of all your devices is perfect enough, all the
features supported by the driver can be enabled at start-up. However,
if only one has a flaw for some SCSI feature, you can disable the
support by the driver of this feature at linux start-up and enable
this feature after boot-up only for devices that support it safely.
CONFIG_SCSI_NCR53C8XX_IOMAPPED (default answer: n)
Answer "y" if you suspect your mother board to not allow memory mapped I/O.
May slow down performance a little.
CONFIG_SCSI_NCR53C8XX_TAGGED_QUEUE (default answer: n)
Answer "y" if you are sure that all your SCSI devices that are able to
accept tagged commands will proceed safely.
CONFIG_SCSI_NCR53C8XX_MAX_TAGS (default answer: 4)
This option allows you to specify the maximum number of tagged commands
that can be queued to a device.
CONFIG_SCSI_NCR53C8XX_SYNC (default answer: 5)
This option allows you to specify the frequency in MHz the driver
will use at boot time for synchronous data transfer negotiations.
This frequency can be changed later with the "setsync" control command.
0 means "asynchronous data transfers".
CONFIG_SCSI_NCR53C8XX_FORCE_SYNC_NEGO (default answer: n)
Force synchronous negotiation for all SCSI-2 devices.
Some SCSI-2 devices do not report this feature in byte 7 of inquiry
response but do support it properly (TAMARACK scanners for example).
CONFIG_SCSI_NCR53C8XX_NO_DISCONNECT (default and only reasonnable answer: n)
If you suspect a device of yours does not properly support disconnections,
you can answer "y". Then, all SCSI devices will never disconnect the bus
even while performing long SCSI operations.
CONFIG_SCSI_NCR53C8XX_SYMBIOS_COMPAT
Genuine SYMBIOS boards use GPIO0 in output for controller LED and GPIO3
bit as a flag indicating singled-ended/differential interface.
If all the boards of your system are genuine SYMBIOS boards or use
BIOS and drivers from SYMBIOS, you would want to enable this option.
This option must NOT be enabled if your system has at least one 53C8XX
based scsi board with a vendor-specific BIOS.
For example, Tekram DC-390/U, DC-390/W and DC-390/F scsi controllers
use a vendor-specific BIOS and are known to not use SYMBIOS compatible
GPIO wiring. So, this option must not be enabled if your system has
such a board installed.
CONFIG_SCSI_NCR53C8XX_NVRAM_DETECT
Enable support for reading the serial NVRAM data on Symbios and
some Symbios compatible cards, and Tekram DC390W/U/F cards. Useful for
systems with more than one Symbios compatible controller where at least
one has a serial NVRAM, or for a system with a mixture of Symbios and
Tekram cards. Enables setting the boot order of host adaptors
to something other than the default order or "reverse probe" order.
Also enables Symbios and Tekram cards to be distinguished so
CONFIG_SCSI_NCR53C8XX_SYMBIOS_COMPAT may be set in a system with a
mixture of Symbios and Tekram cards so the Symbios cards can make use of
the full range of Symbios features, differential, led pin, without
causing problems for the Tekram card(s).
10. Boot setup commands
10.1 Syntax
Setup commands can be passed to the driver at boot time.
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:
lilo: linux root=/dev/hda2 ncr53c8xx=tags:4,sync:10,debug:0x200
- enable tagged commands, up to 4 tagged commands queued.
- set synchronous negotiation speed to 10 Mega-transfers / second.
- set DEBUG_NEGO flag.
For the moment, the integer list of arguments is disgarded by the driver.
It will be used in the future in order to allow a per controller setup.
Each string argument must be specified as "keyword:value". Only lower-case
characters and digits are allowed.
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
Special features
Only apply to 810A, 825A, 860 and 875 controllers.
Have no effect with normal 810 and 825.
specf:y enabled
specf:n disabled
Ultra SCSI support
Only apply to 860 and 875 controllers.
Have no effect with other ones.
ultra:y enabled
ultra:n disabled
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.
If the driver is configured with a maximum of 4 queued commands, tags:4 is
the right argument to specify.
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
#factor < 50 Fast SCSI-2
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
#x is an integer value combining the following power-of-2 values:
DEBUG_ALLOC 0x1
DEBUG_PHASE 0x2
DEBUG_POLL 0x4
DEBUG_QUEUE 0x8
DEBUG_RESULT 0x10
DEBUG_SCATTER 0x20
DEBUG_SCRIPT 0x40
DEBUG_TINY 0x80
DEBUG_TIMING 0x100
DEBUG_NEGO 0x200
DEBUG_TAGS 0x400
DEBUG_FREEZE 0x800
DEBUG_RESTART 0x1000
You can play safely with DEBUG_NEGO. However, some of these flags may
generate bunches of syslog messages.
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).
This is a maximum value. The driver set the burst length according to chip
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
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
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
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>
Available option bits:
0x1: Set PCI cache-line size register if not set.
0x2: Set write and invalidate bit in PCI command register.
0x4: Increase if necessary PCI latency timer according to burst max.
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
Boot fail safe
safe:y load the following assumed fail safe initial setup
master parity disabled mpar:n
scsi parity enabled spar:y
disconnections not allowed disc:n
special features disabled specf:n
ultra scsi disabled ultra:n
force sync negotiation disabled fsn:n
reverse probe disabled revprob:n
PCI fix up disabled pcifix:0
serial NVRAM enabled nvram:y
verbosity level 2 verb:2
tagged command queuing disabled tags:0
synchronous negotiation disabled sync:255
debug flags none debug:0
burst length from BIOS settings burst:255
LED support disabled led:0
wide support disabled wide:0
settle time 10 seconds settle:10
differential support from BIOS settings diff:1
irq mode from BIOS settings irqm:1
10.3 Advised boot setup commands
If the driver has been configured with default options, the equivalent
boot setup is:
ncr53c8xx=mpar:y,spar:y,disc:y,specf:y,fsn:n,ultra:y,fsn:n,revprob:n,verb:1\
tags:0,sync:50,debug:0,burst:7,led:0,wide:1,settle:2,diff:0,irqm:0
For an installation diskette or a safe but not fast system,
boot setup can be:
ncr53c8xx=safe:y,mpar:y,disc:y
ncr53c8xx=safe:y,disc:y
ncr53c8xx=safe:y,mpar:y
ncr53c8xx=safe:y
My personnal system works flawlessly with the following equivalent setup:
ncr53c8xx=mpar:y,spar:y,disc:y,specf:y,fsn:n,ultra:y,fsn:n,revprob:n,verb:1\
tags:8,sync:12,debug:0,burst:7,led:1,wide:1,settle:2,diff:0,irqm:0
The driver prints its actual setup when verbosity level is 2. You can try
"ncr53c8xx=verb:2" to get the "static" setup of the driver, or add "verb:2"
to your boot setup command in order to check the actual setup the driver is
using.
10.4 PCI configuration fix-up boot option
pcifix:<option bits>
Available option bits:
0x1: Set PCI cache-line size register if not set.
0x2: Set write and invalidate bit in PCI command register.
Use 'pcifix:3' in order to allow the driver to fix both PCI features.
These options only apply to new SYMBIOS chips 810A, 825A, 860 and 875
and are only supported for Pentium and 486 class processors.
Recent SYMBIOS 53C8XX scsi processors are able to use PCI read multiple
and PCI write and invalidate commands. These features require the
cache line size register to be properly set in the PCI configuration
space of the chips. On the other hand, chips will use PCI write and
invalidate commands only if the corresponding bit is set to 1 in the
PCI command register.
Not all PCI bioses set the PCI cache line register and the PCI write and
invalidate bit in the PCI configuration space of 53C8XX chips.
Optimized PCI accesses may be broken for some PCI/memory controllers or
make problems with some PCI boards.
This fix-up works flawlessly on my system.
(MB Triton HX / 53C875 / 53C810A)
I use these options at my own risks as you will do if you decide to
use them too.
10.5 Serial NVRAM support boot option
nvram:n do not look for serial NVRAM
nvram:y test controllers for onboard serial NVRAM
This option is described below (see 17. Serial NVRAM support).
When this option is enabled, the driver tries to detect all boards using
a Serial NVRAM. This memory is used to hold user set up parameters.
The parameters the driver is able to get from the NVRAM depend on the
data format used, as follow:
Tekram format Symbios format
General and host parameters
Boot order N Y
Host SCSI ID Y Y
SCSI parity checking Y Y
Verbose boot messages N Y
SCSI devices parameters
Synchronous transfer speed Y Y
Wide 16 / Narrow Y Y
Tagged Command Queuing enabled Y Y
Disconnections enabled Y Y
Scan at boot time N Y
In order to speed up the system boot, for each device configured without
the "scan at boot time" option, the driver forces an error on the
first TEST UNIT READY command received for this device.
Some SDMS BIOS revisions seem to be unable to boot cleanly with very fast
hard disks. In such a situation you cannot configure the NVRAM with
optimized parameters value.
The 'nvram' boot option can be entered in hexadecimal form in order
to ignore some options configured in the NVRAM, as follow:
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
My Atlas Wide only boots cleanly in 8 bits asynchronous data transfer
mode. However, it works flawlessly at 20 MB/second with the driver.
Using "nvram=0x7" allows me to boot in 8 bits/async and to let the driver
use its setup for synchronous and wide negotiations.
11. Some constants and flags of the ncr53c8xx.h header file
Some of these are defined from the configuration parameters. To
change other "defines", you must edit the header file. Do that only
if you know what you are doing.
SCSI_NCR_SETUP_ULTRA_SUPPORT (default: defined)
Ultra SCSI support.
Can be changed by the following boot setup command:
ncr53c8xx=ultra:n
SCSI_NCR_SETUP_SPECIAL_FEATURES (default: defined)
If defined, the driver will enable some special features according
to chip and revision id.
For 810A, 860, 825A and 875 scsi chips, this option enables support
of features that reduce load of PCI bus and memory accesses during
scsi transfer processing: burst op-code fetch, read multiple,
read line, prefetch, cache line line, write and invalidate,
burst 128 (875 only), large dma fifo (875 only), offset 16 (875 only).
Can be changed by the following boot setup command:
ncr53c8xx=specf:n
SCSI_NCR_IOMAPPED (default: not defined)
If defined, normal I/O is forced.
SCSI_NCR_SHARE_IRQ (default: defined)
If defined, request shared IRQ.
SCSI_NCR_MAX_TAGS (default: 4)
Maximum number of simultaneous tagged commands to a device.
Can be changed by "settags <target> <maxtags>"
SCSI_NCR_SETUP_DEFAULT_SYNC (default: 50)
Transfer period factor the driver will use at boot time for synchronous
negotiation. 0 means asynchronous.
Can be changed by "setsync <target> <period factor>"
SCSI_NCR_SETUP_DEFAULT_TAGS (default: 4)
Default number of simultaneous tagged commands to a device.
< 1 means tagged command queuing disabled at start-up.
SCSI_NCR_ALWAYS_SIMPLE_TAG (default: defined)
Use SIMPLE TAG for read and write commands.
Can be changed by "setorder <ordered|simple|default>"
SCSI_NCR_SETUP_DISCONNECTION (default: defined)
If defined, targets are allowed to disconnect.
SCSI_NCR_SETUP_FORCE_SYNC_NEGO (default: not defined)
If defined, synchronous negotiation is tried for all SCSI-2 devices.
Can be changed by "setsync <target> <period>"
SCSI_NCR_SETUP_MASTER_PARITY (default: defined)
If defined, master parity checking is enabled.
SCSI_NCR_SETUP_MASTER_PARITY (default: defined)
If defined, SCSI parity checking is enabled.
SCSI_NCR_PROFILE (default: defined)
If defined, profiling information is gathered.
SCSI_NCR_MAX_SCATTER (default: 128)
Scatter list size of the driver ccb.
SCSI_NCR_MAX_TARGET (default: 16)
Max number of targets per host.
SCSI_NCR_MAX_HOST (default: 2)
Max number of host controllers.
SCSI_NCR_SETTLE_TIME (default: 2)
Number of seconds the driver will wait after reset.
SCSI_NCR_TIMEOUT_ALERT (default: 3)
If a pending command will time out after this amount of seconds,
an ordered tag is used for the next command.
Avoids timeouts for unordered tagged commands.
SCSI_NCR_CAN_QUEUE (default: 7*SCSI_NCR_MAX_TAGS)
Max number of commands that can be queued to a host.
SCSI_NCR_CMD_PER_LUN (default: SCSI_NCR_MAX_TAGS)
Max number of commands queued to a host for a device.
SCSI_NCR_SG_TABLESIZE (default: SCSI_NCR_MAX_SCATTER-1)
Max size of the Linux scatter/gather list.
SCSI_NCR_MAX_LUN (default: 8)
Max number of LUNs per target.
12. Installation
12.1 Provided files
Driver and common files:
README.ncr53c8xx : this file
ChangeLog.ncr53c8xx : change log
ConfigHelp.ncr53c8xx : Part of Configure.help about the driver
ncr53c8xx.h : definitions
ncr53c8xx.c : the driver code
scsitag.c : command tool to enable tagged queue
conf.modules : sample of /etc/conf.modules
Install.ncr53c8xx : installation script
Patch-1.2.13.ncr53c8xx : patch for linux-1.2.13
Patch-2.0.29.ncr53c8xx : patch for linux-2.0.29
You must untar the distribution with the following command:
tar zxvf ncrBsd2Linux-2.2b-src.tar.gz
The sub-directory ncr53c8xx-2.2b will be created. Change to this directory.
12.2 Installation procedure
This install script has been tested with linux-1.2.13 and 2.0.29.
This procedure copies the new driver files to the kernel tree and
applies a patch to some files of the kernel tree.
If your linux directory is at the standard location
"/usr/src/linux", just enter:
Install.ncr53c8xx
Else enter:
Install.ncr53c8xx <your_linux_directory>
Make the kernel:
Change to linux source directory
Configure with NCR53C7,8XX support = N
Configure with NCR53C8XX support = Y (or m)
Make dependancies
Make the kernel (use make zdisk first)
Make and install modules if you have configured with 'm'
13. Control commands under linux-1.2.13
Profiling data and control commands using the proc SCSI file system
are not available for linux-1.2.13. The only control command
available is "scsitag" which allows you to enable tagged command
queuing support after linux boot-up.
Tagged command queueing is disabled by default at system startup.
You can enable tagged queue per device with the following command:
scsitag device_name (ex: scsitag /dev/sda)
Use "cc -o scsitag scsitag.c" to create the "scsitag" executable.
14. Known problems
14.1 Tagged commands with Iomega Jaz device
I have not tried this device, however it has been reported to me the
following: This device is capable of Tagged command queuing. However
while spinning up, it rejects Tagged commands. This behaviour is
conforms to 6.8.2 of SCSI-2 specifications. The current behaviour of
the driver in that situation is not satisfying. So do not enable
Tagged command queuing for devices that are able to spin down. The
other problem that may appear is timeouts. The only way to avoid
timeouts seems to edit linux/drivers/scsi/sd.c and to increase the
current timeout values.
14.2 Device names change when another controller is added.
When you add a new NCR53C8XX chip based controller to a system that already
has one or more controllers of this family, it may happen that the order
the driver registers them to the kernel causes problems due to device
name changes.
When at least one controller uses NvRAM, SDMS BIOS version 4 allows you to
define the order the BIOS will scan the scsi boards. The driver attaches
controllers according to BIOS information if NvRAM detect option is set.
If your controllers do not have NvRAM, you can:
- Ask the driver to probe chip ids in reverse order from the boot command
line: ncr53c8xx=revprob:y
- Make appropriate changes in the fstab.
- Use the 'scsidev' tool from Eric Youngdale.
15. SCSI problem troubleshooting
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:
- SCSI bus cables
- terminations at both end of the SCSI chain
- linux syslog messages (some of them may help you)
If you donnot find the source of problems, you can configure the
driver with no features enabled.
- only asynchronous data transfers
- tagged commands disabled
- disconnections not allowed
Now, if your SCSI bus is ok, your system have every chance to work
with this safe configuration but performances will not be optimal.
If it still fails, then you can send your problem description to
appropriate mailing lists or news-groups. Send me a copy in order to
be sure I will receive it. Obviously, a bug in the driver code is
possible.
My email address: Gerard Roudier <groudier@club-internet.fr>
Allowing disconnections is important if you use several devices on
your SCSI bus but often causes problems with buggy devices.
Synchronous data transfers increases throughput of fast devices like
hard disks. Good SCSI hard disks with a large cache gain advantage of
tagged commands queuing.
Try to enable one feature at a time with control commands. For example:
- echo "setsync all 25" >/proc/scsi/ncr53c8xx/0
Will enable fast synchronous data transfer negotiation for all targets.
- echo "setflag 3" >/proc/scsi/ncr53c8xx/0
Will reset flags (no_sync) for target 3, and so will allow it to disconnect
the SCSI Bus.
- echo "settags 3 4" >/proc/scsi/ncr53c8xx/0
Will enable tagged command queuing for target 3 if that device supports it.
Once you have found the device and the feature that cause problems, just
disable that feature for that device.
16. Synchonous transfer negotiation tables
Tables below have been created by calling the routine the driver uses
for synchronisation negotiation timing calculation and chip setting.
The first table corresponds to Ultra chips 53875 and 53C860 with 80 MHz
clock and 5 clock divisors.
The second one has been calculated by setting the scsi clock to 40 Mhz
and using 4 clock divisors and so applies to all NCR53C8XX chips in fast
SCSI-2 mode.
Periods are in nano-seconds and speeds are in Mega-transfers per second.
1 Mega-transfers/second means 1 MB/s with 8 bits SCSI and 2 MB/s with
Wide16 SCSI.
16.1 Synchronous timings for 53C875 and 53C860 Ultra-SCSI controllers
----------------------------------------------
Negotiated NCR settings
Factor Period Speed Period Speed
------ ------ ------ ------ ------
12 50 20.000 50 20.000
13 52 19.230 62 16.000
14 56 17.857 62 16.000
15 60 16.666 62 16.000
16 64 15.625 75 13.333
17 68 14.705 75 13.333
18 72 13.888 75 13.333
19 76 13.157 87 11.428
20 80 12.500 87 11.428
21 84 11.904 87 11.428
22 88 11.363 93 10.666
23 92 10.869 93 10.666
24 96 10.416 100 10.000
25 100 10.000 100 10.000
26 104 9.615 112 8.888
27 108 9.259 112 8.888
28 112 8.928 112 8.888
29 116 8.620 125 8.000
30 120 8.333 125 8.000
31 124 8.064 125 8.000
32 128 7.812 131 7.619
33 132 7.575 150 6.666
34 136 7.352 150 6.666
35 140 7.142 150 6.666
36 144 6.944 150 6.666
37 148 6.756 150 6.666
38 152 6.578 175 5.714
39 156 6.410 175 5.714
40 160 6.250 175 5.714
41 164 6.097 175 5.714
42 168 5.952 175 5.714
43 172 5.813 175 5.714
44 176 5.681 187 5.333
45 180 5.555 187 5.333
46 184 5.434 187 5.333
47 188 5.319 200 5.000
48 192 5.208 200 5.000
49 196 5.102 200 5.000
16.2 Synchronous timings for fast SCSI-2 53C8XX controllers
----------------------------------------------
Negotiated NCR settings
Factor Period Speed Period Speed
------ ------ ------ ------ ------
25 100 10.000 100 10.000
26 104 9.615 125 8.000
27 108 9.259 125 8.000
28 112 8.928 125 8.000
29 116 8.620 125 8.000
30 120 8.333 125 8.000
31 124 8.064 125 8.000
32 128 7.812 131 7.619
33 132 7.575 150 6.666
34 136 7.352 150 6.666
35 140 7.142 150 6.666
36 144 6.944 150 6.666
37 148 6.756 150 6.666
38 152 6.578 175 5.714
39 156 6.410 175 5.714
40 160 6.250 175 5.714
41 164 6.097 175 5.714
42 168 5.952 175 5.714
43 172 5.813 175 5.714
44 176 5.681 187 5.333
45 180 5.555 187 5.333
46 184 5.434 187 5.333
47 188 5.319 200 5.000
48 192 5.208 200 5.000
49 196 5.102 200 5.000
17. Serial NVRAM (added by Richard Waltham: dormouse@farsrobt.demon.co.uk)
17.1 Features
Enabling serial NVRAM support enables detection of the serial NVRAM included
on Symbios and some Symbios compatible host adaptors, and Tekram boards. The
serial NVRAM is used by Symbios and Tekram to hold set up parameters for the
host adaptor and it's attached drives.
The Symbios NVRAM also holds data on the boot order of host adaptors in a
system with more than one host adaptor. This enables the order of scanning
the cards for drives to be changed from the default used during host adaptor
detection.
This can be done to a limited extent at the moment using "reverse probe" but
this only changes the order of detection of different types of cards. The
NVRAM boot order settings can do this as well as change the order the same
types of cards are scanned in, something "reverse probe" cannot do.
Tekram boards using Symbios chips, DC390W/F/U, which have NVRAM are detected
and this is used to distinguish between Symbios compatible and Tekram host
adaptors. This is used to disable the Symbios compatible "diff" setting
incorrectly set on Tekram boards if the CONFIG_SCSI_53C8XX_SYMBIOS_COMPAT
configuration parameter is set enabling both Symbios and Tekram boards to be
used together with the Symbios cards using all their features, including
"diff" support. ("led pin" support for Symbios compatible cards can remain
enabled when using Tekram cards. It does nothing useful for Tekram host
adaptors but does not cause problems either.)
17.2 Symbios NVRAM layout
typical data at NVRAM address 0x100 (53c810a NVRAM)
-----------------------------------------------------------
00 00
64 01
8e 0b
00 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00
04 00 0f 00 00 10 00 50 00 00 01 00 00 62
04 00 03 00 00 10 00 58 00 00 01 00 00 63
04 00 01 00 00 10 00 48 00 00 01 00 00 61
00 00 00 00 00 00 00 00 00 00 00 00 00 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
fe fe
00 00
00 00
-----------------------------------------------------------
NVRAM layout details
NVRAM Address 0x000-0x0ff not used
0x100-0x26f initialised data
0x270-0x7ff not used
general layout
header - 6 bytes,
data - 356 bytes (checksum is byte sum of this data)
trailer - 6 bytes
---
total 368 bytes
data area layout
controller set up - 20 bytes
boot configuration - 56 bytes (4x14 bytes)
device set up - 128 bytes (16x8 bytes)
unused (spare?) - 152 bytes (19x8 bytes)
---
total 356 bytes
-----------------------------------------------------------
header
00 00 - ?? start marker
64 01 - byte count (lsb/msb excludes header/trailer)
8e 0b - checksum (lsb/msb excludes header/trailer)
-----------------------------------------------------------
controller set up
00 30 00 00 00 00 07 00 00 00 00 00 00 00 07 04 10 04 00 00
| | |
| | -- host ID
| --flag bits 2
| 0x00000001= scan order hi->low
| (default 0x00 - scan low->hi)
--flag bits 1
0x00000001 scam enable
0x00000010 parity enable
0x00000100 verbose boot msgs
remaining bytes unknown - they do not appear to change in my
current set up for any of the controllers.
default set up is identical for 53c810a and 53c875 NVRAM
-----------------------------------------------------------
boot configuration
boot order set by order of the devices in this table
04 00 0f 00 00 10 00 50 00 00 01 00 00 62 -- 1st controller
04 00 03 00 00 10 00 58 00 00 01 00 00 63 2nd controller
04 00 01 00 00 10 00 48 00 00 01 00 00 61 3rd controller
00 00 00 00 00 00 00 00 00 00 00 00 00 00 4th controller
| | | | | | | |
| | | | | | ---- PCI io port adr
| | | | | --0x01 init/scan at boot time
| | | | --PCI device/function number (0xdddddfff)
| | ----- ?? PCI vendor ID (lsb/msb)
----PCI device ID (lsb/msb)
?? use of this data is a guess but seems reasonable
remaining bytes unknown - they do not appear to change in my
current set up
default set up is identical for 53c810a and 53c875 NVRAM
-----------------------------------------------------------
device set up (up to 16 devices - includes controller)
0f 00 08 08 64 00 0a 00 - id 0
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00
0f 00 08 08 64 00 0a 00 - id 15
| | | | | |
| | | | ----timeout (lsb/msb)
| | | --synch period (0x?? 40 Mtrans/sec- fast 40) (probably 0x28)
| | | (0x30 20 Mtrans/sec- fast 20)
| | | (0x64 10 Mtrans/sec- fast )
| | | (0xc8 5 Mtrans/sec)
| | | (0x00 asynchronous)
| | -- ?? max sync offset (0x08 in NVRAM on 53c810a)
| | (0x10 in NVRAM on 53c875)
| --device bus width (0x08 narrow)
| (0x10 16 bit wide)
--flag bits
0x00000001 - disconnect enabled
0x00000010 - scan at boot time
0x00000100 - scan luns
0x00001000 - queue tags enabled
remaining bytes unknown - they do not appear to change in my
current set up
?? use of this data is a guess but seems reasonable
(but it could be max bus width)
default set up for 53c810a NVRAM
default set up for 53c875 NVRAM - bus width - 0x10
- sync offset ? - 0x10
- sync period - 0x30
-----------------------------------------------------------
?? spare device space (32 bit bus ??)
00 00 00 00 00 00 00 00 (19x8bytes)
.
.
00 00 00 00 00 00 00 00
default set up is identical for 53c810a and 53c875 NVRAM
-----------------------------------------------------------
trailer
fe fe - ? end marker ?
00 00
00 00
default set up is identical for 53c810a and 53c875 NVRAM
-----------------------------------------------------------
17.3 Tekram NVRAM layout
nvram 64x16 (1024 bit)
Drive settings
Drive ID 0-15 (addr 0x0yyyy0 = device setup, yyyy = ID)
(addr 0x0yyyy1 = 0x0000)
x x x x x x x x x x x x x x x x
| | | | | | | | |
| | | | | | | | ----- parity check 0 - off
| | | | | | | | 1 - on
| | | | | | | |
| | | | | | | ------- sync neg 0 - off
| | | | | | | 1 - on
| | | | | | |
| | | | | | --------- disconnect 0 - off
| | | | | | 1 - on
| | | | | |
| | | | | ----------- start cmd 0 - off
| | | | | 1 - on
| | | | |
| | | | -------------- tagged cmds 0 - off
| | | | 1 - on
| | | |
| | | ---------------- wide neg 0 - off
| | | 1 - on
| | |
--------------------------- sync rate 0 - 10.0 Mtrans/sec
1 - 8.0
2 - 6.6
3 - 5.7
4 - 5.0
5 - 4.0
6 - 3.0
7 - 2.0
7 - 2.0
8 - 20.0
9 - 16.7
a - 13.9
b - 11.9
Global settings
Host flags 0 (addr 0x100000, 32)
x x x x x x x x x x x x x x x x
| | | | | | | | | | | |
| | | | | | | | ----------- host ID 0x00 - 0x0f
| | | | | | | |
| | | | | | | ----------------------- support for 0 - off
| | | | | | | > 2 drives 1 - on
| | | | | | |
| | | | | | ------------------------- support drives 0 - off
| | | | | | > 1Gbytes 1 - on
| | | | | |
| | | | | --------------------------- bus reset on 0 - off
| | | | | power on 1 - on
| | | | |
| | | | ----------------------------- active neg 0 - off
| | | | 1 - on
| | | |
| | | -------------------------------- imm seek 0 - off
| | | 1 - on
| | |
| | ---------------------------------- scan luns 0 - off
| | 1 - on
| |
-------------------------------------- removable 0 - disable
as BIOS dev 1 - boot device
2 - all
Host flags 1 (addr 0x100001, 33)
x x x x x x x x x x x x x x x x
| | | | | |
| | | --------- boot delay 0 - 3 sec
| | | 1 - 5
| | | 2 - 10
| | | 3 - 20
| | | 4 - 30
| | | 5 - 60
| | | 6 - 120
| | |
--------------------------- max tag cmds 0 - 2
1 - 4
2 - 8
3 - 16
4 - 32
Host flags 2 (addr 0x100010, 34)
x x x x x x x x x x x x x x x x
|
----- F2/F6 enable 0 - off ???
1 - on ???
checksum (addr 0x111111)
checksum = 0x1234 - (sum addr 0-63)
----------------------------------------------------------------------------
default nvram data:
0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
0x0037 0x0000 0x0037 0x0000 0x0037 0x0000 0x0037 0x0000
0x0f07 0x0400 0x0001 0x0000 0x0000 0x0000 0x0000 0x0000
0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000
0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000
0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0xfbbc
===============================================================================
End of NCR53C8XX driver README file
