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 LUN's 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
