Documentation/scsi/in2000.txt - kernel/msm-4.19 - Gitiles


 UPDATE NEWS: version 1.33 - 26 Aug 98

    Interrupt management in this driver has become, over
    time, increasingly odd and difficult to explain - this
    has been mostly due to my own mental inadequacies. In
    recent kernels, it has failed to function at all when
    compiled for SMP. I've fixed that problem, and after
    taking a fresh look at interrupts in general, greatly
    reduced the number of places where they're fiddled
    with. Done some heavy testing and it looks very good.
    The driver now makes use of the __initfunc() and
    __initdata macros to save about 4k of kernel memory.
    Once again, the same code works for both 2.0.xx and
    2.1.xx kernels.

 UPDATE NEWS: version 1.32 - 28 Mar 98

    Removed the check for legal IN2000 hardware versions:
    It appears that the driver works fine with serial
    EPROMs (the 8-pin chip that defines hardware rev) as
    old as 2.1, so we'll assume that all cards are OK.

 UPDATE NEWS: version 1.31 - 6 Jul 97

    Fixed a bug that caused incorrect SCSI status bytes to be
    returned from commands sent to LUNs greater than 0. This
    means that CDROM changers work now! Fixed a bug in the
    handling of command-line arguments when loaded as a module.
    Also put all the header data in in2000.h where it belongs.
    There are no longer any differences between this driver in
    the 2.1.xx source tree and the 2.0.xx tree, as of 2.0.31
    and 2.1.45 (or is it .46?) - this makes things much easier
    for me...

 UPDATE NEWS: version 1.30 - 14 Oct 96

    Fixed a bug in the code that sets the transfer direction
    bit (DESTID_DPD in the WD_DESTINATION_ID register). There
    are quite a few SCSI commands that do a write-to-device;
    now we deal with all of them correctly. Thanks to Joerg
    Dorchain for catching this one.

 UPDATE NEWS: version 1.29 - 24 Sep 96

    The memory-mapped hardware on the card is now accessed via
    the 'readb()' and 'readl()' macros - required by the new
    memory management scheme in the 2.1.x kernel series.
    As suggested by Andries Brouwer, 'bios_param()' no longer
    forces an artificial 1023 track limit on drives. Also
    removed some kludge-code left over from struggles with
    older (buggy) compilers.

 UPDATE NEWS: version 1.28 - 07 May 96

    Tightened up the "interrupts enabled/disabled" discipline
    in 'in2000_queuecommand()' and maybe 1 or 2 other places.
    I _think_ it may have been a little too lax, causing an
    occasional crash during full moon. A fully functional
    /proc interface is now in place - if you want to play
    with it, start by doing 'cat /proc/scsi/in2000/0'. You
    can also use it to change a few run-time parameters on
    the fly, but it's mostly for debugging. The curious
    should take a good look at 'in2000_proc_info()' in the
    in2000.c file to get an understanding of what it's all
    about; I figure that people who are really into it will
    want to add features suited to their own needs...
    Also, sync is now DISABLED by default.

 UPDATE NEWS: version 1.27 - 10 Apr 96

    Fixed a well-hidden bug in the adaptive-disconnect code
    that would show up every now and then during extreme
    heavy loads involving 2 or more simultaneously active
    devices. Thanks to Joe Mack for keeping my nose to the
    grindstone on this one.

 UPDATE NEWS: version 1.26 - 07 Mar 96

    1.25 had a nasty bug that bit people with swap partitions
    and tape drives. Also, in my attempt to guess my way
    through Intel assembly language, I made an error in the
    inline code for IO writes. Made a few other changes and
    repairs - this version (fingers crossed) should work well.

 UPDATE NEWS: version 1.25 - 05 Mar 96

    Kernel 1.3.70 interrupt mods added; old kernels still OK.
    Big help from Bill Earnest and David Willmore on speed
    testing and optimizing: I think there's a real improvement
    in this area.
    New! User-friendly command-line interface for LILO and
    module loading - the old method is gone, so you'll need
    to read the comments for 'setup_strings' near the top
    of in2000.c. For people with CDROM's or other devices
    that have a tough time with sync negotiation, you can
    now selectively disable sync on individual devices -
    search for the 'nosync' keyword in the command-line
    comments. Some of you disable the BIOS on the card, which
    caused the auto-detect function to fail; there is now a
    command-line option to force detection of a ROM-less card.

 UPDATE NEWS: version 1.24a - 24 Feb 96

    There was a bug in the synchronous transfer code. Only
    a few people downloaded before I caught it - could have
    been worse.

 UPDATE NEWS: version 1.24 - 23 Feb 96

    Lots of good changes. Advice from Bill Earnest resulted
    in much better detection of cards, more efficient usage
    of the fifo, and (hopefully) faster data transfers. The
    jury is still out on speed - I hope it's improved some.
    One nifty new feature is a cool way of doing disconnect/
    reselect. The driver defaults to what I'm calling
    'adaptive disconnect' - meaning that each command is
    evaluated individually as to whether or not it should be
    run with the option to disconnect/reselect (if the device
    chooses), or as a "SCSI-bus-hog". When several devices
    are operating simultaneously, disconnects are usually an
    advantage. In a single device system, or if only 1 device
    is being accessed, transfers usually go faster if disconnects
    are not allowed.


 The default arguments (you get these when you don't give an 'in2000'
 command-line argument, or you give a blank argument) will cause
 the driver to do adaptive disconnect, synchronous transfers, and a
 minimum of debug messages. If you want to fool with the options,
 search for 'setup_strings' near the top of the in2000.c file and
 check the 'hostdata->args' section in in2000.h - but be warned! Not
 everything is working yet (some things will never work, probably).
 I believe that disabling disconnects (DIS_NEVER) will allow you
 to choose a LEVEL2 value higher than 'L2_BASIC', but I haven't
 spent a lot of time testing this. You might try 'ENABLE_CLUSTERING'
 to see what happens: my tests showed little difference either way.
 There's also a define called 'DEFAULT_SX_PER'; this sets the data
 transfer speed for the asynchronous mode. I've put it at 500 ns
 despite the fact that the card could handle settings of 376 or
 252, because higher speeds may be a problem with poor quality
 cables or improper termination; 500 ns is a compromise. You can
 choose your own default through the command-line with the
 'period' keyword.


 ------------------------------------------------
 ***********  DIP switch settings  **************
 ------------------------------------------------

    sw1-1 sw1-2    BIOS address (hex)
    -----------------------------------------
     off   off     C8000 - CBFF0
     on    off     D8000 - DBFF0
     off   on      D0000 - D3FF0
     on    on      BIOS disabled

    sw1-3 sw1-4    IO port address (hex)
    ------------------------------------
     off   off     220 - 22F
     on    off     200 - 20F
     off   on      110 - 11F
     on    on      100 - 10F

    sw1-5 sw1-6 sw1-7    Interrupt
    ------------------------------
     off   off   off     15
     off   on    off     14
     off   off   on      11
     off   on    on      10
     on    -     -       disabled

    sw1-8 function depends on BIOS version. In earlier versions this
    controlled synchronous data transfer support for MSDOS:
       off = disabled
       on  = enabled
    In later ROMs (starting with 01.3 in April 1994) sw1-8 controls
    the "greater than 2 disk drive" feature that first appeared in
    MSDOS 5.0 (ignored by Linux):
       off = 2 drives maximum
       on  = 7 drives maximum

    sw1-9    Floppy controller
    --------------------------
     off     disabled
     on      enabled

 ------------------------------------------------

    I should mention that Drew Eckhardt's 'Generic NCR5380' sources
    were my main inspiration, with lots of reference to the IN2000
    driver currently distributed in the kernel source. I also owe
    much to a driver written by Hamish Macdonald for Linux-m68k(!).
    And to Eric Wright for being an ALPHA guinea pig. And to Bill
    Earnest for 2 tons of great input and information. And to David
    Willmore for extensive 'bonnie' testing. And to Joe Mack for
    continual testing and feedback.


             John Shifflett    jshiffle@netcom.com

	UPDATE NEWS: version 1.33 - 26 Aug 98

	Interrupt management in this driver has become, over
	time, increasingly odd and difficult to explain - this
	has been mostly due to my own mental inadequacies. In
	recent kernels, it has failed to function at all when
	compiled for SMP. I've fixed that problem, and after
	taking a fresh look at interrupts in general, greatly
	reduced the number of places where they're fiddled
	with. Done some heavy testing and it looks very good.
	The driver now makes use of the __initfunc() and
	__initdata macros to save about 4k of kernel memory.
	Once again, the same code works for both 2.0.xx and
	2.1.xx kernels.

	UPDATE NEWS: version 1.32 - 28 Mar 98

	Removed the check for legal IN2000 hardware versions:
	It appears that the driver works fine with serial
	EPROMs (the 8-pin chip that defines hardware rev) as
	old as 2.1, so we'll assume that all cards are OK.

	UPDATE NEWS: version 1.31 - 6 Jul 97

	Fixed a bug that caused incorrect SCSI status bytes to be
	returned from commands sent to LUNs greater than 0. This
	means that CDROM changers work now! Fixed a bug in the
	handling of command-line arguments when loaded as a module.
	Also put all the header data in in2000.h where it belongs.
	There are no longer any differences between this driver in
	the 2.1.xx source tree and the 2.0.xx tree, as of 2.0.31
	and 2.1.45 (or is it .46?) - this makes things much easier
	for me...

	UPDATE NEWS: version 1.30 - 14 Oct 96

	Fixed a bug in the code that sets the transfer direction
	bit (DESTID_DPD in the WD_DESTINATION_ID register). There
	are quite a few SCSI commands that do a write-to-device;
	now we deal with all of them correctly. Thanks to Joerg
	Dorchain for catching this one.

	UPDATE NEWS: version 1.29 - 24 Sep 96

	The memory-mapped hardware on the card is now accessed via
	the 'readb()' and 'readl()' macros - required by the new
	memory management scheme in the 2.1.x kernel series.
	As suggested by Andries Brouwer, 'bios_param()' no longer
	forces an artificial 1023 track limit on drives. Also
	removed some kludge-code left over from struggles with
	older (buggy) compilers.

	UPDATE NEWS: version 1.28 - 07 May 96

	Tightened up the "interrupts enabled/disabled" discipline
	in 'in2000_queuecommand()' and maybe 1 or 2 other places.
	I _think_ it may have been a little too lax, causing an
	occasional crash during full moon. A fully functional
	/proc interface is now in place - if you want to play
	with it, start by doing 'cat /proc/scsi/in2000/0'. You
	can also use it to change a few run-time parameters on
	the fly, but it's mostly for debugging. The curious
	should take a good look at 'in2000_proc_info()' in the
	in2000.c file to get an understanding of what it's all
	about; I figure that people who are really into it will
	want to add features suited to their own needs...
	Also, sync is now DISABLED by default.

	UPDATE NEWS: version 1.27 - 10 Apr 96

	Fixed a well-hidden bug in the adaptive-disconnect code
	that would show up every now and then during extreme
	heavy loads involving 2 or more simultaneously active
	devices. Thanks to Joe Mack for keeping my nose to the
	grindstone on this one.

	UPDATE NEWS: version 1.26 - 07 Mar 96

	1.25 had a nasty bug that bit people with swap partitions
	and tape drives. Also, in my attempt to guess my way
	through Intel assembly language, I made an error in the
	inline code for IO writes. Made a few other changes and
	repairs - this version (fingers crossed) should work well.

	UPDATE NEWS: version 1.25 - 05 Mar 96

	Kernel 1.3.70 interrupt mods added; old kernels still OK.
	Big help from Bill Earnest and David Willmore on speed
	testing and optimizing: I think there's a real improvement
	in this area.
	New! User-friendly command-line interface for LILO and
	module loading - the old method is gone, so you'll need
	to read the comments for 'setup_strings' near the top
	of in2000.c. For people with CDROM's or other devices
	that have a tough time with sync negotiation, you can
	now selectively disable sync on individual devices -
	search for the 'nosync' keyword in the command-line
	comments. Some of you disable the BIOS on the card, which
	caused the auto-detect function to fail; there is now a
	command-line option to force detection of a ROM-less card.

	UPDATE NEWS: version 1.24a - 24 Feb 96

	There was a bug in the synchronous transfer code. Only
	a few people downloaded before I caught it - could have
	been worse.

	UPDATE NEWS: version 1.24 - 23 Feb 96

	Lots of good changes. Advice from Bill Earnest resulted
	in much better detection of cards, more efficient usage
	of the fifo, and (hopefully) faster data transfers. The
	jury is still out on speed - I hope it's improved some.
	One nifty new feature is a cool way of doing disconnect/
	reselect. The driver defaults to what I'm calling
	'adaptive disconnect' - meaning that each command is
	evaluated individually as to whether or not it should be
	run with the option to disconnect/reselect (if the device
	chooses), or as a "SCSI-bus-hog". When several devices
	are operating simultaneously, disconnects are usually an
	advantage. In a single device system, or if only 1 device
	is being accessed, transfers usually go faster if disconnects
	are not allowed.



	The default arguments (you get these when you don't give an 'in2000'
	command-line argument, or you give a blank argument) will cause
	the driver to do adaptive disconnect, synchronous transfers, and a
	minimum of debug messages. If you want to fool with the options,
	search for 'setup_strings' near the top of the in2000.c file and
	check the 'hostdata->args' section in in2000.h - but be warned! Not
	everything is working yet (some things will never work, probably).
	I believe that disabling disconnects (DIS_NEVER) will allow you
	to choose a LEVEL2 value higher than 'L2_BASIC', but I haven't
	spent a lot of time testing this. You might try 'ENABLE_CLUSTERING'
	to see what happens: my tests showed little difference either way.
	There's also a define called 'DEFAULT_SX_PER'; this sets the data
	transfer speed for the asynchronous mode. I've put it at 500 ns
	despite the fact that the card could handle settings of 376 or
	252, because higher speeds may be a problem with poor quality
	cables or improper termination; 500 ns is a compromise. You can
	choose your own default through the command-line with the
	'period' keyword.


	------------------------------------------------
	********* DIP switch settings ************
	------------------------------------------------

	sw1-1 sw1-2 BIOS address (hex)
	-----------------------------------------
	off off C8000 - CBFF0
	on off D8000 - DBFF0
	off on D0000 - D3FF0
	on on BIOS disabled

	sw1-3 sw1-4 IO port address (hex)
	------------------------------------
	off off 220 - 22F
	on off 200 - 20F
	off on 110 - 11F
	on on 100 - 10F

	sw1-5 sw1-6 sw1-7 Interrupt
	------------------------------
	off off off 15
	off on off 14
	off off on 11
	off on on 10
	on - - disabled

	sw1-8 function depends on BIOS version. In earlier versions this
	controlled synchronous data transfer support for MSDOS:
	off = disabled
	on = enabled
	In later ROMs (starting with 01.3 in April 1994) sw1-8 controls
	the "greater than 2 disk drive" feature that first appeared in
	MSDOS 5.0 (ignored by Linux):
	off = 2 drives maximum
	on = 7 drives maximum

	sw1-9 Floppy controller
	--------------------------
	off disabled
	on enabled

	------------------------------------------------

	I should mention that Drew Eckhardt's 'Generic NCR5380' sources
	were my main inspiration, with lots of reference to the IN2000
	driver currently distributed in the kernel source. I also owe
	much to a driver written by Hamish Macdonald for Linux-m68k(!).
	And to Eric Wright for being an ALPHA guinea pig. And to Bill
	Earnest for 2 tons of great input and information. And to David
	Willmore for extensive 'bonnie' testing. And to Joe Mack for
	continual testing and feedback.


	John Shifflett jshiffle@netcom.com