path: root/Documentation/scsi/in2000.txt
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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/scsi/in2000.txt
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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+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