sym53c8xx_2.txt

linux 内核源代码

	phase:   print information on script interruptions

    Use "setdebug" with no argument to reset debug flags.


8.5 Set flag (no_disc)
 
    setflag <target> <flag>

    target:    target number

    For the moment, only one flag is available:

        no_disc:   not allow target to disconnect.

    Do not specify any flag in order to reset the flag. For example:
    - setflag 4
      will reset no_disc flag for target 4, so will allow it disconnections.
    - setflag all
      will allow disconnection for all devices on the SCSI bus.


8.6 Set verbose level

    setverbose #level

    The driver default verbose level is 1. This command allows to change 
    th driver verbose level after boot-up.

8.7 Reset all logical units of a target

    resetdev <target>

    target:    target number
    The driver will try to send a BUS DEVICE RESET message to the target.

8.8 Abort all tasks of all logical units of a target

    cleardev <target>

    target:    target number
    The driver will try to send a ABORT message to all the logical units 
    of the target.


9. Configuration parameters

Under kernel configuration tools (make menuconfig, for example), it is 
possible to change some default driver configuration parameters.
If the firmware of all your devices is perfect enough, all the
features supported by the driver can be enabled at start-up. However,
if only one has a flaw for some SCSI feature, you can disable the
support by the driver of this feature at linux start-up and enable
this feature after boot-up only for devices that support it safely.

Configuration parameters:

Use normal IO                         (default answer: n)
    Answer "y" if you suspect your mother board to not allow memory mapped I/O.
    May slow down performance a little.

Default tagged command queue depth    (default answer: 16)
    Entering 0 defaults to tagged commands not being used.
    This parameter can be specified from the boot command line.

Maximum number of queued commands     (default answer: 32)
    This option allows you to specify the maximum number of tagged commands 
    that can be queued to a device. The maximum supported value is 255.

Synchronous transfers frequency       (default answer: 80)
    This option allows you to specify the frequency in MHz the driver 
    will use at boot time for synchronous data transfer negotiations.
    0 means "asynchronous data transfers".

10. Boot setup commands

10.1 Syntax

Setup commands can be passed to the driver either at boot time or as
parameters to modprobe, as described in Documentation/kernel-parameters.txt

Example of boot setup command under lilo prompt:

lilo: linux root=/dev/sda2 sym53c8xx.cmd_per_lun=4 sym53c8xx.sync=10 sym53c8xx.debug=0x200

- enable tagged commands, up to 4 tagged commands queued.
- set synchronous negotiation speed to 10 Mega-transfers / second.
- set DEBUG_NEGO flag.

The following command will install the driver module with the same
options as above.

    modprobe sym53c8xx cmd_per_lun=4 sync=10 debug=0x200

10.2 Available arguments

10.2.1  Default number of tagged commands
        cmd_per_lun=0 (or cmd_per_lun=1) tagged command queuing disabled
        cmd_per_lun=#tags (#tags > 1) tagged command queuing enabled
  #tags will be truncated to the max queued commands configuration parameter.

10.2.2 Burst max
        burst=0    burst disabled
        burst=255  get burst length from initial IO register settings.
        burst=#x   burst enabled (1<<#x burst transfers max)
  #x is an integer value which is log base 2 of the burst transfers max.
  By default the driver uses the maximum value supported by the chip.

10.2.3 LED support
        led=1      enable  LED support
        led=0      disable LED support
  Do not enable LED support if your scsi board does not use SDMS BIOS.
  (See 'Configuration parameters')

10.2.4 Differential mode
        diff=0	never set up diff mode
        diff=1	set up diff mode if BIOS set it
        diff=2	always set up diff mode
        diff=3	set diff mode if GPIO3 is not set

10.2.5 IRQ mode
        irqm=0     always open drain
        irqm=1     same as initial settings (assumed BIOS settings)
        irqm=2     always totem pole

10.2.6 Check SCSI BUS 
        buschk=<option bits>

    Available option bits:
        0x0:   No check.
        0x1:   Check and do not attach the controller on error.  
        0x2:   Check and just warn on error.

10.2.7 Suggest a default SCSI id for hosts
        hostid=255	no id suggested.
        hostid=#x   (0 < x < 7) x suggested for hosts SCSI id.

    If a host SCSI id is available from the NVRAM, the driver will ignore 
    any value suggested as boot option. Otherwise, if a suggested value 
    different from 255 has been supplied, it will use it. Otherwise, it will 
    try to deduce the value previously set in the hardware and use value 
    7 if the hardware value is zero.

10.2.8  Verbosity level
        verb=0     minimal
        verb=1     normal
        verb=2     too much

10.2.9 Debug mode
        debug=0	 clear debug flags
        debug=#x   set debug flags
  #x is an integer value combining the following power-of-2 values:
  DEBUG_ALLOC       0x1
  DEBUG_PHASE       0x2
  DEBUG_POLL        0x4
  DEBUG_QUEUE       0x8
  DEBUG_RESULT     0x10
  DEBUG_SCATTER    0x20
  DEBUG_SCRIPT     0x40
  DEBUG_TINY       0x80
  DEBUG_TIMING    0x100
  DEBUG_NEGO      0x200
  DEBUG_TAGS      0x400
  DEBUG_FREEZE    0x800
  DEBUG_RESTART  0x1000

  You can play safely with DEBUG_NEGO. However, some of these flags may 
  generate bunches of syslog messages. 

10.2.10 Settle delay
        settle=n	delay for n seconds

  After a bus reset, the driver will delay for n seconds before talking
  to any device on the bus.  The default is 3 seconds and safe mode will
  default it to 10.

10.2.11 Serial NVRAM
	NB: option not currently implemented.
        nvram=n     do not look for serial NVRAM
        nvram=y     test controllers for onboard serial NVRAM
        (alternate binary form)
        nvram=<bits options>
        0x01   look for NVRAM  (equivalent to nvram=y)
        0x02   ignore NVRAM "Synchronous negotiation" parameters for all devices
        0x04   ignore NVRAM "Wide negotiation"  parameter for all devices
        0x08   ignore NVRAM "Scan at boot time" parameter for all devices
        0x80   also attach controllers set to OFF in the NVRAM (sym53c8xx only)

10.2.12 Exclude a host from being attached
        excl=<io_address>,...

    Prevent host at a given io address from being attached.
    For example 'excl=0xb400,0xc000' indicate to the 
    driver not to attach hosts at address 0xb400 and 0xc000.

10.3 Converting from old style options

Previously, the sym2 driver accepted arguments of the form
	sym53c8xx=tags:4,sync:10,debug:0x200

As a result of the new module parameters, this is no longer available.
Most of the options have remained the same, but tags has become
cmd_per_lun to reflect its different purposes.  The sample above would
be specified as:
	modprobe sym53c8xx cmd_per_lun=4 sync=10 debug=0x200

or on the kernel boot line as:
	sym53c8xx.cmd_per_lun=4 sym53c8xx.sync=10 sym53c8xx.debug=0x200

10.4 SCSI BUS checking boot option.

When this option is set to a non-zero value, the driver checks SCSI lines 
logic state, 100 micro-seconds after having asserted the SCSI RESET line.
The driver just reads SCSI lines and checks all lines read FALSE except RESET.
Since SCSI devices shall release the BUS at most 800 nano-seconds after SCSI 
RESET has been asserted, any signal to TRUE may indicate a SCSI BUS problem.
Unfortunately, the following common SCSI BUS problems are not detected:
- Only 1 terminator installed.
- Misplaced terminators.
- Bad quality terminators.
On the other hand, either bad cabling, broken devices, not conformant 
devices, ... may cause a SCSI signal to be wrong when te driver reads it.

15. SCSI problem troubleshooting

15.1 Problem tracking

Most SCSI problems are due to a non conformant SCSI bus or too buggy
devices.  If unfortunately you have SCSI problems, you can check the
following things:

- SCSI bus cables
- terminations at both end of the SCSI chain
- linux syslog messages (some of them may help you)

If you do not find the source of problems, you can configure the
driver or devices in the NVRAM with minimal features.

- only asynchronous data transfers
- tagged commands disabled
- disconnections not allowed

Now, if your SCSI bus is ok, your system has every chance to work
with this safe configuration but performances will not be optimal.

If it still fails, then you can send your problem description to
appropriate mailing lists or news-groups.  Send me a copy in order to
be sure I will receive it.  Obviously, a bug in the driver code is
possible.

  My current email address: Gerard Roudier <[e-mail]>

Allowing disconnections is important if you use several devices on
your SCSI bus but often causes problems with buggy devices.
Synchronous data transfers increases throughput of fast devices like
hard disks.  Good SCSI hard disks with a large cache gain advantage of
tagged commands queuing.

15.2 Understanding hardware error reports

When the driver detects an unexpected error condition, it may display a 
message of the following pattern.

sym0:1: ERROR (0:48) (1-21-65) (f/95/0) @ (script 7c0:19000000).
sym0: script cmd = 19000000
sym0: regdump: da 10 80 95 47 0f 01 07 75 01 81 21 80 01 09 00.

Some fields in such a message may help you understand the cause of the 
problem, as follows:

sym0:1: ERROR (0:48) (1-21-65) (f/95/0) @ (script 7c0:19000000).
.....A.........B.C....D.E..F....G.H..I.......J.....K...L.......

Field A : target number.
  SCSI ID of the device the controller was talking with at the moment the 
  error occurs.

Field B : DSTAT io register (DMA STATUS)
  Bit 0x40 : MDPE Master Data Parity Error
             Data parity error detected on the PCI BUS.
  Bit 0x20 : BF   Bus Fault
             PCI bus fault condition detected
  Bit 0x01 : IID  Illegal Instruction Detected
             Set by the chip when it detects an Illegal Instruction format 
             on some condition that makes an instruction illegal.
  Bit 0x80 : DFE Dma Fifo Empty
             Pure status bit that does not indicate an error.
  If the reported DSTAT value contains a combination of MDPE (0x40), 
  BF (0x20), then the cause may be likely due to a PCI BUS problem.

Field C : SIST io register (SCSI Interrupt Status)
  Bit 0x08 : SGE  SCSI GROSS ERROR
             Indicates that the chip detected a severe error condition 
             on the SCSI BUS that prevents the SCSI protocol from functioning
             properly.
  Bit 0x04 : UDC  Unexpected Disconnection
             Indicates that the device released the SCSI BUS when the chip 
             was not expecting this to happen. A device may behave so to 
             indicate the SCSI initiator that an error condition not reportable              using the SCSI protocol has occurred.
  Bit 0x02 : RST  SCSI BUS Reset
             Generally SCSI targets do not reset the SCSI BUS, although any 
             device on the BUS can reset it at any time.
  Bit 0x01 : PAR  Parity
             SCSI parity error detected.
  On a faulty SCSI BUS, any error condition among SGE (0x08), UDC (0x04) and 
  PAR (0x01) may be detected by the chip. If your SCSI system sometimes 
  encounters such error conditions, especially SCSI GROSS ERROR, then a SCSI 
  BUS problem is likely the cause of these errors.

For fields D,E,F,G and H, you may look into the sym53c8xx_defs.h file 
that contains some minimal comments on IO register bits.
Field D : SOCL  Scsi Output Control Latch
          This register reflects the state of the SCSI control lines the 
          chip want to drive or compare against.
Field E : SBCL  Scsi Bus Control Lines
          Actual value of control lines on the SCSI BUS.
Field F : SBDL  Scsi Bus Data Lines
          Actual value of data lines on the SCSI BUS.
Field G : SXFER  SCSI Transfer
          Contains the setting of the Synchronous Period for output and 
          the current Synchronous offset (offset 0 means asynchronous).
Field H : SCNTL3 Scsi Control Register 3
          Contains the setting of timing values for both asynchronous and 
          synchronous data transfers. 
Field I : SCNTL4 Scsi Control Register 4
          Only meaningful for 53C1010 Ultra3 controllers.

Understanding Fields J, K, L and dumps requires to have good knowledge of 
SCSI standards, chip cores functionnals and internal driver data structures.
You are not required to decode and understand them, unless you want to help 
maintain the driver code.

17. Serial NVRAM (added by Richard Waltham: [e-mail])

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 information is no longer used
as it's fundamentally incompatible with the hotplug PCI model.

Tekram boards using Symbios chips, DC390W/F/U, which have NVRAM are detected
and this is used to distinguish between Symbios compatible and Tekram host 
adaptors. This is used to disable the Symbios compatible "diff" setting
incorrectly set on Tekram boards if the CONFIG_SCSI_53C8XX_SYMBIOS_COMPAT 
configuration parameter is set enabling both Symbios and Tekram boards to be