AIC7xxx Driver for Linux
  
  Introduction
  ----------------------------
  The AIC7xxx SCSI driver adds support for Adaptec (http://www.adaptec.com)
  SCSI controllers and chipsets. Major portions of the driver and driver
  development are shared between both Linux and FreeBSD. Support for the
  AIC-7xxx chipsets have been in the default Linux kernel since approximately
  linux-1.1.x and fairly stable since linux-1.2.x, and are also in FreeBSD
  2.1.0 or later.
  
    Supported cards/chipsets
    ----------------------------
      Adaptec Cards
      ----------------------------
      AHA-274x
      AHA-274xT               
      AHA-2842
      AHA-2910B               
      AHA-2920C
      AHA-2930
      AHA-2930U
      AHA-2930CU
      AHA-2930U2
      AHA-2940               
      AHA-2940W              
      AHA-2940U              
      AHA-2940UW
      AHA-2940UW-PRO
      AHA-2940AU 
      AHA-2940U2W
      AHA-2940U2
      AHA-2940U2B
      AHA-2940U2BOEM
      AHA-2944D              
      AHA-2944WD
      AHA-2944UD
      AHA-2944UWD
      AHA-2950U2
      AHA-2950U2W
      AHA-2950U2B
      AHA-29160M
      AHA-3940
      AHA-3940U
      AHA-3940W
      AHA-3940UW
      AHA-3940AUW
      AHA-3940U2W
      AHA-3950U2B
      AHA-3950U2D
      AHA-3960D
      AHA-39160M
      AHA-3985
      AHA-3985U
      AHA-3985W
      AHA-3985UW
  
      Motherboard Chipsets
      ----------------------------
      AIC-777x   
      AIC-785x
      AIC-786x
      AIC-787x
      AIC-788x
      AIC-789x
      AIC-3860
  
      Bus Types
      ----------------------------
      W - Wide SCSI, SCSI-3, 16bit bus, 68pin connector, will also support
          SCSI-1/SCSI-2 50pin devices, transfer rates up to 20MB/s.
      U - Ultra SCSI, transfer rates up to 40MB/s.
      U2- Ultra 2 SCSI, transfer rates up to 80MB/s.
      D - Differential SCSI.
      T - Twin Channel SCSI. Up to 14 SCSI devices.
  
      AHA-274x - EISA SCSI controller
      AHA-284x - VLB SCSI controller
      AHA-29xx - PCI SCSI controller
      AHA-394x - PCI controllers with two separate SCSI controllers on-board.
      AHA-398x - PCI RAID controllers with three separate SCSI controllers
                 on-board.
  
    Not Supported Devices
    ------------------------------
      Adaptec Cards
      ----------------------------
      AHA-2920 (Only the cards that use the Future Domain chipset are not
                supported, any 2920 cards based on Adaptec AIC chipsets,
  	      such as the 2920C, are supported)
      AAA-13x Raid Adapters
      AAA-113x Raid Port Card
  
      Motherboard Chipsets
      ----------------------------
      AIC-7810
  
      Bus Types
      ----------------------------
      R - Raid Port busses are not supported.
  
      The hardware RAID devices sold by Adaptec are *NOT* supported by this
      driver (and will people please stop emailing me about them, they are
      a totally separate beast from the bare SCSI controllers and this driver

      cannot be retrofitted in any sane manner to support the hardware RAID

      features on those cards - Doug Ledford).
      
  
    People
    ------------------------------
      Justin T Gibbs  gibbs@plutotech.com
        (BSD Driver Author)
      Dan Eischen     deischen@iworks.InterWorks.org
        (Original Linux Driver Co-maintainer)
      Dean Gehnert    deang@teleport.com
        (Original Linux FTP/patch maintainer)
      Jess Johnson    jester@frenzy.com
        (AIC7xxx FAQ author)
      Doug Ledford    dledford@redhat.com
        (Current Linux aic7xxx-5.x.x Driver/Patch/FTP maintainer)
      
      Special thanks go to John Aycock (aycock@cpsc.ucalgary.ca), the original
      author of the driver. John has since retired from the project. Thanks
      again for all his work!
      
    Mailing list
    ------------------------------
      There is a mailing list available for users who want to track development
      and converse with other users and developers. This list is for both
      FreeBSD and Linux support of the AIC7xxx chipsets.
  
      To subscribe to the AIC7xxx mailing list send mail to the list server,
      with "subscribe AIC7xxx" in the body (no Subject: required):
          To: majordomo@FreeBSD.ORG
          ---
          subscribe AIC7xxx
  
      To unsubscribe from the list, send mail to the list server with:
          To: majordomo@FreeBSD.ORG
          ---
          unsubscribe AIC7xxx
  
      Send regular messages and replies to: AIC7xxx@FreeBSD.ORG
      
    Boot Command line options
    ------------------------------
      "aic7xxx=no_reset" -  Eliminate the SCSI bus reset during startup.
          Some SCSI devices need the initial reset that this option disables
  	in order to work.  If you have problems at bootup, please make sure
  	you aren't using this option.
  	
      "aic7xxx=reverse_scan" - Certain PCI motherboards scan for devices at
          bootup by scanning from the highest numbered PCI device to the
  	lowest numbered PCI device, others do just the opposite and scan
  	from lowest to highest numbered PCI device.  There is no reliable
  	way to autodetect this ordering.  So, we default to the most common
  	order, which is lowest to highest.  Then, in case your motherboard
  	scans from highest to lowest, we have this option.  If your BIOS
  	finds the drives on controller A before controller B but the linux
  	kernel finds your drives on controller B before A, then you should
  	use this option.
  	
      "aic7xxx=extended" - Force the driver to detect extended drive translation
          on your controller.  This helps those people who have cards without
          a SEEPROM make sure that linux and all other operating systems think
          the same way about your hard drives.
  
      "aic7xxx=scbram" - Some cards have external SCB RAM that can be used to
          give the card more hardware SCB slots.  This allows the driver to use
  	that SCB RAM.  Without this option, the driver won't touch the SCB
  	RAM because it is known to cause problems on a few cards out there
  	(such as 3985 class cards).
  	
      "aic7xxx=irq_trigger:x" - Replace x with either 0 or 1 to force the kernel
          to use the correct IRQ type for your card.  This only applies to EISA
          based controllers.  On these controllers, 0 is for Edge triggered
          interrupts, and 1 is for Level triggered interrupts.  If you aren't
          sure or don't know which IRQ trigger type your EISA card uses, then
          let the kernel autodetect the trigger type.
  	
      "aic7xxx=verbose" - This option can be used in one of two ways.  If you
          simply specify aic7xxx=verbose, then the kernel will automatically
  	pick the default set of verbose messages for you to see.
  	Alternatively, you can specify the command as 
  	"aic7xxx=verbose:0xXXXX" where the X entries are replaced with
  	hexadecimal digits.  This option is a bit field type option.  For
  	a full listing of the available options, search for the 
  	#define VERBOSE_xxxxxx lines in the aic7xxx.c file.  If you want
  	verbose messages, then it is recommended that you simply use the
  	aic7xxx=verbose variant of this command.
  	
      "aic7xxx=pci_parity:x" - This option controls whether or not the driver
          enables PCI parity error checking on the PCI bus.  By default, this
          checking is disabled.  To enable the checks, simply specify pci_parity
          with no value afterwords.  To reverse the parity from even to odd,
          supply any number other than 0 or 255.  In short:
            pci_parity     - Even parity checking (even is the normal PCI parity)
            pci_parity:x   - Where x > 0, Odd parity checking
            pci_parity:0   - No check (default)
          NOTE: In order to get Even PCI parity checking, you must use the
          version of the option that does not include the : and a number at
          the end (unless you want to enter exactly 2^32 - 1 as the number).
  	
      "aic7xxx=no_probe" - This option will disable the probing for any VLB
          based 2842 controllers and any EISA based controllers.  This is
  	needed on certain newer motherboards where the normal EISA I/O ranges
  	have been claimed by other PCI devices.  Probing on those machines
  	will often result in the machine crashing or spontaneously rebooting
  	during startup.  Examples of machines that need this are the
  	Dell PowerEdge 6300 machines.
  
      "aic7xxx=seltime:2" - This option controls how long the card waits
          during a device selection sequence for the device to respond.
  	The original SCSI spec says that this "should be" 256ms.  This
  	is generally not required with modern devices.  However, some
  	very old SCSI I devices need the full 256ms.  Most modern devices
  	can run fine with only 64ms.  The default for this option is
  	64ms.  If you need to change this option, then use the following
  	table to set the proper value in the example above:
  	  0  -  256ms
  	  1  -  128ms
  	  2  -   64ms
  	  3  -   32ms
  	
      "aic7xxx=panic_on_abort" - This option is for debugging and will cause
          the driver to panic the linux kernel and freeze the system the first
  	time the drivers abort or reset routines are called.  This is most
  	helpful when some problem causes infinite reset loops that scroll too
  	fast to see.  By using this option, you can write down what the errors
  	actually are and send that information to me so it can be fixed.
  	
      "aic7xxx=dump_card" - This option will print out the *entire* set of
          configuration registers on the card during the init sequence.  This
  	is a debugging aid used to see exactly what state the card is in
  	when we finally finish our initialization routines.  If you don't
  	have documentation on the chipsets, this will do you absolutely
  	no good unless you are simply trying to write all the information
  	down in order to send it to me.
  	
      "aic7xxx=dump_sequencer" - This is the same as the above options except
          that instead of dumping the register contents on the card, this
  	option dumps the contents of the sequencer program RAM.  This gives
  	the ability to verify that the instructions downloaded to the

  	card's sequencer are indeed what they are supposed to be.  Again,

  	unless you have documentation to tell you how to interpret these
  	numbers, then it is totally useless.
  	
      "aic7xxx=override_term:0xffffffff" - This option is used to force the
      	termination on your SCSI controllers to a particular setting.  This
  	is a bit mask variable that applies for up to 8 aic7xxx SCSI channels.
  	Each channel gets 4 bits, divided as follows:
  	bit   3   2   1   0
  	      |   |   |   Enable/Disable Single Ended Low Byte Termination
  	      |   |   En/Disable Single Ended High Byte Termination
  	      |   En/Disable Low Byte LVD Termination
  	      En/Disable High Byte LVD Termination
  
  	The upper 2 bits that deal with LVD termination only apply to Ultra2

  	controllers.  Furthermore, due to the current Ultra2 controller

  	designs, these bits are tied together such that setting either bit
  	enables both low and high byte LVD termination.  It is not possible
  	to only set high or low byte LVD termination in this manner.  This is
  	an artifact of the BIOS definition on Ultra2 controllers.  For other
  	controllers, the only important bits are the two lowest bits.  Setting
  	the higher bits on non-Ultra2 controllers has no effect.  A few
  	examples of how to use this option:
  
  	Enable low and high byte termination on a non-ultra2 controller that
  	is the first aic7xxx controller (the correct bits are 0011), 
  	aic7xxx=override_term:0x3
  
  	Enable all termination on the third aic7xxx controller, high byte
  	termination on the second aic7xxx controller, and low and high byte
  	SE termination on the first aic7xxx controller 
  	(bits are 1111 0010 0011), 
  	aic7xxx=override_term:0xf23
  	
  	No attempt has been made to make this option non-cryptic.  It really
  	shouldn't be used except in dire circumstances, and if that happens,
  	I'm probably going to be telling you what to set this to anyway :)
  
      "aic7xxx=stpwlev:0xffffffff" - This option is used to control the STPWLEV
          bit in the DEVCONFIG PCI register.  Currently, this is one of the
  	very few registers that we have absolutely *no* way of detecting
  	what the variable should be.  It depends entirely on how the chipset
  	and external terminators were coupled by the card/motherboard maker.
  	Further, a chip reset (at power up) always sets this bit to 0.  If
  	there is no BIOS to run on the chipset/card (such as with a 2910C
  	or a motherboard controller with the BIOS totally disabled) then
  	the variable may not get set properly.  Of course, if the proper
  	setting was 0, then that's what it would be after the reset, but if
  	the proper setting is actually 1.....you get the picture.  Now, since
  	we can't detect this at all, I've added this option to force the
  	setting.  If you have a BIOS on your controller then you should never
  	need to use this option.  However, if you are having lots of SCSI
  	reset problems and can't seem to get them knocked out, this may help.
  
  	Here's a test to know for certain if you need this option.  Make
  	a boot floppy that you can use to boot your computer up and that
  	will detect the aic7xxx controller.  Next, power down your computer.
  	While it's down, unplug all SCSI cables from your Adaptec SCSI
  	controller.  Boot the system back up to the Adaptec EZ-SCSI BIOS
  	and then make sure that termination is enabled on your adapter (if
  	you have an Adaptec BIOS of course).  Next, boot up the floppy you
  	made and wait for it to detect the aic7xxx controller.  If the kernel
  	finds the controller fine, says scsi : x hosts and then tries to
  	detect your devices like normal, up to the point where it fails to
  	mount your root file system and panics, then you're fine.  If, on
  	the other hand, the system goes into an infinite reset loop, then
  	you need to use this option and/or the previous option to force the
  	proper termination settings on your controller.   If this happens,
  	then you next need to figure out what your settings should be.
  
  	To find the correct settings, power your machine back down, connect
  	back up the SCSI cables, and boot back into your machine like normal.
  	However, boot with the aic7xxx=verbose:0x39 option.  Record the
  	initial DEVCONFIG values for each of your aic7xxx controllers as
  	they are listed, and also record what the machine is detecting as
  	the proper termination on your controllers.  NOTE: the order in

  	which the initial DEVCONFIG values are printed out is not guaranteed

  	to be the same order as the SCSI controllers are registered.  The
  	above option and this option both work on the order of the SCSI
  	controllers as they are registered, so make sure you match the right
  	DEVCONFIG values with the right controllers if you have more than
  	one aic7xxx controller.
  
  	Once you have the detected termination settings and the initial
  	DEVCONFIG values for each controller, then figure out what the
  	termination on each of the controllers *should* be.  Hopefully, that
  	part is correct, but it could possibly be wrong if there is
  	bogus cable detection logic on your controller or something similar.
  	If all the controllers have the correct termination settings, then
  	don't set the aic7xxx=override_term variable at all, leave it alone.
  	Next, on any controllers that go into an infinite reset loop when
  	you unplug all the SCSI cables, get the starting DEVCONFIG value.
  	If the initial DEVCONFIG value is divisible by 2, then the correct
  	setting for that controller is 0.  If it's an odd number, then
  	the correct setting for that controller is 1.  For any other
  	controllers that didn't have an infinite reset problem, then reverse
  	the above options.  If DEVCONFIG was even, then the correct setting
  	is 1, if not then the correct setting is 0.
  
  	Now that you know what the correct setting was for each controller,
  	we need to encode that into the aic7xxx=stpwlev:0x... variable.
  	This variable is a bit field encoded variable.  Bit 0 is for the first
  	aic7xxx controller, bit 1 for the next, etc.  Put all these bits
  	together and you get a number.  For example, if the third aic7xxx
  	needed a 1, but the second and first both needed a 0, then the bits
  	would be 100 in binary.  This then translates to 0x04.  You would
  	therefore set aic7xxx=stpwlev:0x04.  This is fairly standard binary
  	to hexadecimal conversions here.  If you aren't up to speed on the
  	binary->hex conversion then send an email to the aic7xxx mailing
  	list and someone can help you out.
  
      "aic7xxx=tag_info:{{8,8..},{8,8..},..}" - This option is used to disable
          or enable Tagged Command Queueing (TCQ) on specific devices.  As of
  	driver version 5.1.11, TCQ is now either on or off by default
  	according to the setting you choose during the make config process.

  	In order to en/disable TCQ for certain devices at boot time, a user

  	may use this boot param.  The driver will then parse this message out
          and en/disable the specific device entries that are present based upon
          the value given.  The param line is parsed in the following manner:
  
            { - first instance indicates the start of this parameter values
                second instance is the start of entries for a particular
                device entry
            } - end the entries for a particular host adapter, or end the entire
                set of parameter entries
            , - move to next entry.  Inside of a set of device entries, this
                moves us to the next device on the list.  Outside of device
                entries, this moves us to the next host adapter
            . - Same effect as , but is safe to use with insmod.
            x - the number to enter into the array at this position.  
                0 = Enable tagged queueing on this device and use the default
                    queue depth
                1-254 = Enable tagged queueing on this device and use this
                        number as the queue depth
                255 = Disable tagged queueing on this device.
                Note: anything above 32 for an actual queue depth is wasteful
                      and not recommended.
  
          A few examples of how this can be used:
  
          tag_info:{{8,12,,0,,255,4}}
            This line will only effect the first aic7xxx card registered.  It
            will set scsi id 0 to a queue depth of 8, id 1 to 12, leave id 2
            at the default, set id 3 to tagged queueing enabled and use the
            default queue depth, id 4 default, id 5 disabled, and id 6 to 4.
            Any not specified entries stay at the default value, repeated
            commas with no value specified will simply increment to the next id
            without changing anything for the missing values.
  
          tag_info:{,,,{,,,255}}
            First, second, and third adapters at default values.  Fourth
            adapter, id 3 is disabled.  Notice that leading commas simply
  	  increment what the first number effects, and there are no need
  	  for trailing commas.  When you close out an adapter, or the
  	  entire entry, anything not explicitly set stays at the default
  	  value.
  
          A final note on this option.  The scanner I used for this isn't
          perfect or highly robust.  If you mess the line up, the worst that
          should happen is that the line will get ignored.  If you don't
          close out the entire entry with the final bracket, then any other
          aic7xxx options after this will get ignored.  So, in general, be
          sure of what you are entering, and after you have it right, just
          add it to the lilo.conf file so there won't be any mistakes.  As
          a means of checking this parser, the entire tag_info array for
          each card is now printed out in the /proc/scsi/aic7xxx/x file.  You
          can use that to verify that your options were parsed correctly. 
          
      Boot command line options may be combined to form the proper set of options
      a user might need.  For example, the following is valid:
      
      aic7xxx=verbose,extended,irq_trigger:1
      
      The only requirement is that individual options be separated by a comma or
      a period on the command line.
          
    Module Loading command options
    ------------------------------
      When loading the aic7xxx driver as a module, the exact same options are
      available to the user.  However, the syntax to specify the options changes
      slightly.  For insmod, you need to wrap the aic7xxx= argument in quotes
      and replace all ',' with '.'.  So, for example, a valid insmod line
      would be:
  
      insmod aic7xxx aic7xxx='verbose.irq_trigger:1.extended'
  
      This line should result in the *exact* same behaviour as if you typed
      it in at the lilo prompt and the driver was compiled into the kernel
      instead of being a module.  The reason for the single quote is so that
      the shell won't try to interpret anything in the line, such as {. 
      Insmod assumes any options starting with a letter instead of a number
      is a character string (which is what we want) and by switching all of
      the commas to periods, insmod won't interpret this as more than one
      string and write junk into our binary image.  I consider it a bug in
      the insmod program that even if you wrap your string in quotes (quotes

      that pass the shell mind you and that insmod sees) it still treats

      a comma inside of those quotes as starting a new variable, resulting
      in memory scribbles if you don't switch the commas to periods.
  
  
    Kernel Compile options
    ------------------------------
      The various kernel compile time options for this driver are now fairly

      well documented in the file drivers/scsi/Kconfig.  In order to

      see this documentation, you need to use one of the advanced configuration
      programs (menuconfig and xconfig).  If you are using the "make menuconfig"
      method of configuring your kernel, then you would simply highlight the
      option in question and hit the ? key.  If you are using the "make xconfig"
      method of configuring your kernel, then simply click on the help button
      next to the option you have questions about.  The help information from
      the Configure.help file will then get automatically displayed.
  
    /proc support
    ------------------------------
      The /proc support for the AIC7xxx can be found in the /proc/scsi/aic7xxx/
      directory. That directory contains a file for each SCSI controller in
      the system. Each file presents the current configuration and transfer
      statistics (enabled with #define in aic7xxx.c) for each controller.
  
      Thanks to Michael Neuffer for his upper-level SCSI help, and
      Matthew Jacob for statistics support.
  
    Debugging the driver
    ------------------------------
      Should you have problems with this driver, and would like some help in
      getting them solved, there are a couple debugging items built into
      the driver to facilitate getting the needed information from the system.
      In general, I need a complete description of the problem, with as many
      logs as possible concerning what happens.  To help with this, there is
      a command option aic7xxx=panic_on_abort.  This option, when set, forces
      the driver to panic the kernel on the first SCSI abort issued by the
      mid level SCSI code.  If your system is going to reset loops and you
      can't read the screen, then this is what you need.  Not only will it
      stop the system, but it also prints out a large amount of state
      information in the process.  Second, if you specify the option
      "aic7xxx=verbose:0x1ffff", the system will print out *SOOOO* much
      information as it runs that you won't be able to see anything.
      However, this can actually be very useful if your machine simply
      locks up when trying to boot, since it will pin-point what was last
      happening (in regards to the aic7xxx driver) immediately prior to
      the lockup.  This is really only useful if your machine simply can
      not boot up successfully.  If you can get your machine to run, then
      this will produce far too much information.
  
    FTP sites
    ------------------------------
      ftp://ftp.redhat.com/pub/aic/
        - Out of date.  I used to keep stuff here, but too many people
          complained about having a hard time getting into Red Hat's ftp
  	server.  So use the web site below instead.
      ftp://ftp.pcnet.com/users/eischen/Linux/
        - Dan Eischen's driver distribution area
      ftp://ekf2.vsb.cz/pub/linux/kernel/aic7xxx/ftp.teleport.com/
        - European Linux mirror of Teleport site
  
    Web sites
    ------------------------------
      http://people.redhat.com/dledford/
        - My web site, also the primary aic7xxx site with several related
          pages.
  
  Dean W. Gehnert
  deang@teleport.com
  
  $Revision: 3.0 $
  
  Modified by Doug Ledford 1998-2000