Changelog for ide cd

/*
 * 1.00  Oct 31, 1994 -- Initial version.
 * 1.01  Nov  2, 1994 -- Fixed problem with starting request in
 *                       cdrom_check_status.
 * 1.03  Nov 25, 1994 -- leaving unmask_intr[] as a user-setting (as for disks)
 * (from mlord)       -- minor changes to cdrom_setup()
 *                    -- renamed ide_dev_s to ide_drive_t, enable irq on command
 * 2.00  Nov 27, 1994 -- Generalize packet command interface;
 *                       add audio ioctls.
 * 2.01  Dec  3, 1994 -- Rework packet command interface to handle devices
 *                       which send an interrupt when ready for a command.
 * 2.02  Dec 11, 1994 -- Cache the TOC in the driver.
 *                       Don't use SCMD_PLAYAUDIO_TI; it's not included
 *                       in the current version of ATAPI.
 *                       Try to use LBA instead of track or MSF addressing
 *                       when possible.
 *                       Don't wait for READY_STAT.
 * 2.03  Jan 10, 1995 -- Rewrite block read routines to handle block sizes
 *                       other than 2k and to move multiple sectors in a
 *                       single transaction.
 * 2.04  Apr 21, 1995 -- Add work-around for Creative Labs CD220E drives.
 *                       Thanks to Nick Saw <cwsaw@pts7.pts.mot.com> for
 *                       help in figuring this out.  Ditto for Acer and
 *                       Aztech drives, which seem to have the same problem.
 * 2.04b May 30, 1995 -- Fix to match changes in ide.c version 3.16 -ml
 * 2.05  Jun  8, 1995 -- Don't attempt to retry after an illegal request
 *                        or data protect error.
 *                       Use HWIF and DEV_HWIF macros as in ide.c.
 *                       Always try to do a request_sense after
 *                        a failed command.
 *                       Include an option to give textual descriptions
 *                        of ATAPI errors.
 *                       Fix a bug in handling the sector cache which
 *                        showed up if the drive returned data in 512 byte
 *                        blocks (like Pioneer drives).  Thanks to
 *                        Richard Hirst <srh@gpt.co.uk> for diagnosing this.
 *                       Properly supply the page number field in the
 *                        MODE_SELECT command.
 *                       PLAYAUDIO12 is broken on the Aztech; work around it.
 * 2.05x Aug 11, 1995 -- lots of data structure renaming/restructuring in ide.c
 *                       (my apologies to Scott, but now ide-cd.c is independent)
 * 3.00  Aug 22, 1995 -- Implement CDROMMULTISESSION ioctl.
 *                       Implement CDROMREADAUDIO ioctl (UNTESTED).
 *                       Use input_ide_data() and output_ide_data().
 *                       Add door locking.
 *                       Fix usage count leak in cdrom_open, which happened
 *                        when a read-write mount was attempted.
 *                       Try to load the disk on open.
 *                       Implement CDROMEJECT_SW ioctl (off by default).
 *                       Read total cdrom capacity during open.
 *                       Rearrange logic in cdrom_decode_status.  Issue
 *                        request sense commands for failed packet commands
 *                        from here instead of from cdrom_queue_packet_command.
 *                        Fix a race condition in retrieving error information.
 *                       Suppress printing normal unit attention errors and
 *                        some drive not ready errors.
 *                       Implement CDROMVOLREAD ioctl.
 *                       Implement CDROMREADMODE1/2 ioctls.
 *                       Fix race condition in setting up interrupt handlers
 *                        when the `serialize' option is used.
 * 3.01  Sep  2, 1995 -- Fix ordering of reenabling interrupts in
 *                        cdrom_queue_request.
 *                       Another try at using ide_[input,output]_data.
 * 3.02  Sep 16, 1995 -- Stick total disk capacity in partition table as well.
 *                       Make VERBOSE_IDE_CD_ERRORS dump failed command again.
 *                       Dump out more information for ILLEGAL REQUEST errs.
 *                       Fix handling of errors occurring before the
 *                        packet command is transferred.
 *                       Fix transfers with odd bytelengths.
 * 3.03  Oct 27, 1995 -- Some Creative drives have an id of just `CD'.
 *                       `DCI-2S10' drives are broken too.
 * 3.04  Nov 20, 1995 -- So are Vertos drives.
 * 3.05  Dec  1, 1995 -- Changes to go with overhaul of ide.c and ide-tape.c
 * 3.06  Dec 16, 1995 -- Add support needed for partitions.
 *                       More workarounds for Vertos bugs (based on patches
 *                        from Holger Dietze <dietze@aix520.informatik.uni-leipzig.de>).
 *                       Try to eliminate byteorder assumptions.
 *                       Use atapi_cdrom_subchnl struct definition.
 *                       Add STANDARD_ATAPI compilation option.
 * 3.07  Jan 29, 1996 -- More twiddling for broken drives: Sony 55D,
 *                        Vertos 300.
 *                       Add NO_DOOR_LOCKING configuration option.
 *                       Handle drive_cmd requests w/NULL args (for hdparm -t).
 *                       Work around sporadic Sony55e audio play problem.
 * 3.07a Feb 11, 1996 -- check drive->id for NULL before dereferencing, to fix
 *                        problem with "hde=cdrom" with no drive present.  -ml
 * 3.08  Mar  6, 1996 -- More Vertos workarounds.
 * 3.09  Apr  5, 1996 -- Add CDROMCLOSETRAY ioctl.
 *                       Switch to using MSF addressing for audio commands.
 *                       Reformat to match kernel tabbing style.
 *                       Add CDROM_GET_UPC ioctl.
 * 3.10  Apr 10, 1996 -- Fix compilation error with STANDARD_ATAPI.
 * 3.11  Apr 29, 1996 -- Patch from Heiko Eißfeldt <heiko@colossus.escape.de>
 *                       to remove redundant verify_area calls.
 * 3.12  May  7, 1996 -- Rudimentary changer support.  Based on patches
 *                        from Gerhard Zuber <zuber@berlin.snafu.de>.
 *                       Let open succeed even if there's no loaded disc.
 * 3.13  May 19, 1996 -- Fixes for changer code.
 * 3.14  May 29, 1996 -- Add work-around for Vertos 600.
 *                        (From Hennus Bergman <hennus@sky.ow.nl>.)
 * 3.15  July 2, 1996 -- Added support for Sanyo 3 CD changers
 *                        from Ben Galliart <bgallia@luc.edu> with
 *                        special help from Jeff Lightfoot
 *                        <jeffml@pobox.com>
 * 3.15a July 9, 1996 -- Improved Sanyo 3 CD changer identification
 * 3.16  Jul 28, 1996 -- Fix from Gadi to reduce kernel stack usage for ioctl.
 * 3.17  Sep 17, 1996 -- Tweak audio reads for some drives.
 *                       Start changing CDROMLOADFROMSLOT to CDROM_SELECT_DISC.
 * 3.18  Oct 31, 1996 -- Added module and DMA support.
 *
 * 4.00  Nov 5, 1996   -- New ide-cd maintainer,
 *                                 Erik B. Andersen <andersee@debian.org>
 *                     -- Newer Creative drives don't always set the error
 *                          register correctly.  Make sure we see media changes
 *                          regardless.
 *                     -- Integrate with generic cdrom driver.
 *                     -- CDROMGETSPINDOWN and CDROMSETSPINDOWN ioctls, based on
 *                          a patch from Ciro Cattuto <>.
 *                     -- Call set_device_ro.
 *                     -- Implement CDROMMECHANISMSTATUS and CDROMSLOTTABLE
 *                          ioctls, based on patch by Erik Andersen
 *                     -- Add some probes of drive capability during setup.
 *
 * 4.01  Nov 11, 1996  -- Split into ide-cd.c and ide-cd.h
 *                     -- Removed CDROMMECHANISMSTATUS and CDROMSLOTTABLE
 *                          ioctls in favor of a generalized approach
 *                          using the generic cdrom driver.
 *                     -- Fully integrated with the 2.1.X kernel.
 *                     -- Other stuff that I forgot (lots of changes)
 *
 * 4.02  Dec 01, 1996  -- Applied patch from Gadi Oxman <gadio@netvision.net.il>
 *                          to fix the drive door locking problems.
 *
 * 4.03  Dec 04, 1996  -- Added DSC overlap support.
 * 4.04  Dec 29, 1996  -- Added CDROMREADRAW ioclt based on patch
 *                          by Ales Makarov (xmakarov@sun.felk.cvut.cz)
 *
 * 4.05  Nov 20, 1997  -- Modified to print more drive info on init
 *                        Minor other changes
 *                        Fix errors on CDROMSTOP (If you have a "Dolphin",
 *                          you must define IHAVEADOLPHIN)
 *                        Added identifier so new Sanyo CD-changer works
 *                        Better detection if door locking isn't supported
 *
 * 4.06  Dec 17, 1997  -- fixed endless "tray open" messages  -ml
 * 4.07  Dec 17, 1997  -- fallback to set pc->stat on "tray open"
 * 4.08  Dec 18, 1997  -- spew less noise when tray is empty
 *                     -- fix speed display for ACER 24X, 18X
 * 4.09  Jan 04, 1998  -- fix handling of the last block so we return
 *                         an end of file instead of an I/O error (Gadi)
 * 4.10  Jan 24, 1998  -- fixed a bug so now changers can change to a new
 *                         slot when there is no disc in the current slot.
 *                     -- Fixed a memory leak where info->changer_info was
 *                         malloc'ed but never free'd when closing the device.
 *                     -- Cleaned up the global namespace a bit by making more
 *                         functions static that should already have been.
 * 4.11  Mar 12, 1998  -- Added support for the CDROM_SELECT_SPEED ioctl
 *                         based on a patch for 2.0.33 by Jelle Foks
 *                         <jelle@scintilla.utwente.nl>, a patch for 2.0.33
 *                         by Toni Giorgino <toni@pcape2.pi.infn.it>, the SCSI
 *                         version, and my own efforts.  -erik
 *                     -- Fixed a stupid bug which egcs was kind enough to
 *                         inform me of where "Illegal mode for this track"
 *                         was never returned due to a comparison on data
 *                         types of limited range.
 * 4.12  Mar 29, 1998  -- Fixed bug in CDROM_SELECT_SPEED so write speed is
 *                         now set ionly for CD-R and CD-RW drives.  I had
 *                         removed this support because it produced errors.
 *                         It produced errors _only_ for non-writers. duh.
 * 4.13  May 05, 1998  -- Suppress useless "in progress of becoming ready"
 *                         messages, since this is not an error.
 *                     -- Change error messages to be const
 *                     -- Remove a "\t" which looks ugly in the syslogs
 * 4.14  July 17, 1998 -- Change to pointing to .ps version of ATAPI spec
 *                         since the .pdf version doesn't seem to work...
 *                     -- Updated the TODO list to something more current.
 *
 * 4.15  Aug 25, 1998  -- Updated ide-cd.h to respect machine endianness,
 *                         patch thanks to "Eddie C. Dost" <ecd@skynet.be>
 *
 * 4.50  Oct 19, 1998  -- New maintainers!
 *                         Jens Axboe <axboe@image.dk>
 *                         Chris Zwilling <chris@cloudnet.com>
 *
 * 4.51  Dec 23, 1998  -- Jens Axboe <axboe@image.dk>
 *                      - ide_cdrom_reset enabled since the ide subsystem
 *                         handles resets fine now. <axboe@image.dk>
 *                      - Transfer size fix for Samsung CD-ROMs, thanks to
 *                        "Ville Hallik" <ville.hallik@mail.ee>.
 *                      - other minor stuff.
 *
 * 4.52  Jan 19, 1999  -- Jens Axboe <axboe@image.dk>
 *                      - Detect DVD-ROM/RAM drives
 *
 * 4.53  Feb 22, 1999   - Include other model Samsung and one Goldstar
 *                         drive in transfer size limit.
 *                      - Fix the I/O error when doing eject without a medium
 *                         loaded on some drives.
 *                      - CDROMREADMODE2 is now implemented through
 *                         CDROMREADRAW, since many drives don't support
 *                         MODE2 (even though ATAPI 2.6 says they must).
 *                      - Added ignore parameter to ide-cd (as a module), eg
 *                              insmod ide-cd ignore='hda hdb'
 *                         Useful when using ide-cd in conjunction with
 *                         ide-scsi. TODO: non-modular way of doing the
 *                         same.
 *
 * 4.54  Aug 5, 1999    - Support for MMC2 class commands through the generic
 *                        packet interface to cdrom.c.
 *                      - Unified audio ioctl support, most of it.
 *                      - cleaned up various deprecated verify_area().
 *                      - Added ide_cdrom_packet() as the interface for
 *                        the Uniform generic_packet().
 *                      - bunch of other stuff, will fill in logs later.
 *                      - report 1 slot for non-changers, like the other
 *                        cd-rom drivers. don't report select disc for
 *                        non-changers as well.
 *                      - mask out audio playing, if the device can't do it.
 *
 * 4.55  Sep 1, 1999    - Eliminated the rest of the audio ioctls, except
 *                        for CDROMREADTOC[ENTRY|HEADER]. Some of the drivers
 *                        use this independently of the actual audio handling.
 *                        They will disappear later when I get the time to
 *                        do it cleanly.
 *                      - Minimize the TOC reading - only do it when we
 *                        know a media change has occurred.
 *                      - Moved all the CDROMREADx ioctls to the Uniform layer.
 *                      - Heiko Eißfeldt <heiko@colossus.escape.de> supplied
 *                        some fixes for CDI.
 *                      - CD-ROM leaving door locked fix from Andries
 *                        Brouwer <Andries.Brouwer@cwi.nl>
 *                      - Erik Andersen <andersen@xmission.com> unified
 *                        commands across the various drivers and how
 *                        sense errors are handled.
 *
 * 4.56  Sep 12, 1999   - Removed changer support - it is now in the
 *                        Uniform layer.
 *                      - Added partition based multisession handling.
 *                      - Mode sense and mode select moved to the
 *                        Uniform layer.
 *                      - Fixed a problem with WPI CDS-32X drive - it
 *                        failed the capabilities
 *
 * 4.57  Apr 7, 2000    - Fixed sense reporting.
 *                      - Fixed possible oops in ide_cdrom_get_last_session()
 *                      - Fix locking mania and make ide_cdrom_reset relock
 *                      - Stop spewing errors to log when magicdev polls with
 *                        TEST_UNIT_READY on some drives.
 *                      - Various fixes from Tobias Ringstrom:
 *                        tray if it was locked prior to the reset.
 *                        - cdrom_read_capacity returns one frame too little.
 *                        - Fix real capacity reporting.
 *
 * 4.58  May 1, 2000    - Clean up ACER50 stuff.
 *                      - Fix small problem with ide_cdrom_capacity
 *
 * 4.59  Aug 11, 2000   - Fix changer problem in cdrom_read_toc, we weren't
 *                        correctly sensing a disc change.
 *                      - Rearranged some code
 *                      - Use extended sense on drives that support it for
 *                        correctly reporting tray status -- from
 *                        Michael D Johnson <johnsom@orst.edu>
 * 4.60  Dec 17, 2003   - Add mt rainier support
 *                      - Bump timeout for packet commands, matches sr
 *                      - Odd stuff
 * 4.61  Jan 22, 2004   - support hardware sector sizes other than 2kB,
 *                        Pascal Schmidt <der.eremit@email.de>
 */

Changelog for ide floppy

/*
 * Many thanks to Lode Leroy <Lode.Leroy@www.ibase.be>, who tested so many
 * ALPHA patches to this driver on an EASYSTOR LS-120 ATAPI floppy drive.
 *
 * Ver 0.1   Oct 17 96   Initial test version, mostly based on ide-tape.c.
 * Ver 0.2   Oct 31 96   Minor changes.
 * Ver 0.3   Dec  2 96   Fixed error recovery bug.
 * Ver 0.4   Jan 26 97   Add support for the HDIO_GETGEO ioctl.
 * Ver 0.5   Feb 21 97   Add partitions support.
 *                       Use the minimum of the LBA and CHS capacities.
 *                       Avoid hwgroup->rq == NULL on the last irq.
 *                       Fix potential null dereferencing with DEBUG_LOG.
 * Ver 0.8   Dec  7 97   Increase irq timeout from 10 to 50 seconds.
 *                       Add media write-protect detection.
 *                       Issue START command only if TEST UNIT READY fails.
 *                       Add work-around for IOMEGA ZIP revision 21.D.
 *                       Remove idefloppy_get_capabilities().
 * Ver 0.9   Jul  4 99   Fix a bug which might have caused the number of
 *                        bytes requested on each interrupt to be zero.
 *                        Thanks to <shanos@es.co.nz> for pointing this out.
 * Ver 0.9.sv Jan 6 01   Sam Varshavchik <mrsam@courier-mta.com>
 *                       Implement low level formatting.  Reimplemented
 *                       IDEFLOPPY_CAPABILITIES_PAGE, since we need the srfp
 *                       bit.  My LS-120 drive barfs on
 *                       IDEFLOPPY_CAPABILITIES_PAGE, but maybe it's just me.
 *                       Compromise by not reporting a failure to get this
 *                       mode page.  Implemented four IOCTLs in order to
 *                       implement formatting.  IOCTls begin with 0x4600,
 *                       0x46 is 'F' as in Format.
 *            Jan 9 01   Userland option to select format verify.
 *                       Added PC_SUPPRESS_ERROR flag - some idefloppy drives
 *                       do not implement IDEFLOPPY_CAPABILITIES_PAGE, and
 *                       return a sense error.  Suppress error reporting in
 *                       this particular case in order to avoid spurious
 *                       errors in syslog.  The culprit is
 *                       idefloppy_get_capability_page(), so move it to
 *                       idefloppy_begin_format() so that it's not used
 *                       unless absolutely necessary.
 *                       If drive does not support format progress indication
 *                       monitor the dsc bit in the status register.
 *                       Also, O_NDELAY on open will allow the device to be
 *                       opened without a disk available.  This can be used to
 *                       open an unformatted disk, or get the device capacity.
 * Ver 0.91  Dec 11 99   Added IOMEGA Clik! drive support by
 *                 <paul@paulbristow.net>
 * Ver 0.92  Oct 22 00   Paul Bristow became official maintainer for this
 *                         driver.  Included Powerbook internal zip kludge.
 * Ver 0.93  Oct 24 00   Fixed bugs for Clik! drive
 *                        no disk on insert and disk change now works
 * Ver 0.94  Oct 27 00   Tidied up to remove strstr(Clik) everywhere
 * Ver 0.95  Nov  7 00   Brought across to kernel 2.4
 * Ver 0.96  Jan  7 01   Actually in line with release version of 2.4.0
 *                       including set_bit patch from Rusty Russell
 * Ver 0.97  Jul 22 01   Merge 0.91-0.96 onto 0.9.sv for ac series
 * Ver 0.97.sv Aug 3 01  Backported from 2.4.7-ac3
 * Ver 0.98  Oct 26 01   Split idefloppy_transfer_pc into two pieces to
 *                        fix a lost interrupt problem. It appears the busy
 *                        bit was being deasserted by my IOMEGA ATAPI ZIP 100
 *                        drive before the drive was actually ready.
 * Ver 0.98a Oct 29 01   Expose delay value so we can play.
 * Ver 0.99  Feb 24 02   Remove duplicate code, modify clik! detection code
 *                        to support new PocketZip drives
 */

Changelog for ide tape

/*
 * Ver 0.1   Nov  1 95   Pre-working code :-)
 * Ver 0.2   Nov 23 95   A short backup (few megabytes) and restore procedure
 *                        was successful ! (Using tar cvf ... on the block
 *                        device interface).
 *                       A longer backup resulted in major swapping, bad
 *                        overall Linux performance and eventually failed as
 *                        we received non serial read-ahead requests from the
 *                        buffer cache.
 * Ver 0.3   Nov 28 95   Long backups are now possible, thanks to the
 *                        character device interface. Linux's responsiveness
 *                        and performance doesn't seem to be much affected
 *                        from the background backup procedure.
 *                       Some general mtio.h magnetic tape operations are
 *                        now supported by our character device. As a result,
 *                        popular tape utilities are starting to work with
 *                        ide tapes :-)
 *                       The following configurations were tested:
 *                       1. An IDE ATAPI TAPE shares the same interface
 *                        and irq with an IDE ATAPI CDROM.
 *                       2. An IDE ATAPI TAPE shares the same interface
 *                        and irq with a normal IDE disk.
 *                        Both configurations seemed to work just fine !
 *                        However, to be on the safe side, it is meanwhile
 *                        recommended to give the IDE TAPE its own interface
 *                        and irq.
 *                       The one thing which needs to be done here is to
 *                        add a "request postpone" feature to ide.c,
 *                        so that we won't have to wait for the tape to finish
 *                        performing a long media access (DSC) request (such
 *                        as a rewind) before we can access the other device
 *                        on the same interface. This effect doesn't disturb
 *                        normal operation most of the time because read/write
 *                        requests are relatively fast, and once we are
 *                        performing one tape r/w request, a lot of requests
 *                        from the other device can be queued and ide.c will
 *                        service all of them after this single tape request.
 * Ver 1.0   Dec 11 95   Integrated into Linux 1.3.46 development tree.
 *                       On each read / write request, we now ask the drive
 *                        if we can transfer a constant number of bytes
 *                        (a parameter of the drive) only to its buffers,
 *                        without causing actual media access. If we can't,
 *                        we just wait until we can by polling the DSC bit.
 *                        This ensures that while we are not transferring
 *                        more bytes than the constant referred to above, the
 *                        interrupt latency will not become too high and
 *                        we won't cause an interrupt timeout, as happened
 *                        occasionally in the previous version.
 *                       While polling for DSC, the current request is
 *                        postponed and ide.c is free to handle requests from
 *                        the other device. This is handled transparently to
 *                        ide.c. The hwgroup locking method which was used
 *                        in the previous version was removed.
 *                       Use of new general features which are provided by
 *                        ide.c for use with atapi devices.
 *                        (Programming done by Mark Lord)
 *                       Few potential bug fixes (Again, suggested by Mark)
 *                       Single character device data transfers are now
 *                        not limited in size, as they were before.
 *                       We are asking the tape about its recommended
 *                        transfer unit and send a larger data transfer
 *                        as several transfers of the above size.
 *                        For best results, use an integral number of this
 *                        basic unit (which is shown during driver
 *                        initialization). I will soon add an ioctl to get
 *                        this important parameter.
 *                       Our data transfer buffer is allocated on startup,
 *                        rather than before each data transfer. This should
 *                        ensure that we will indeed have a data buffer.
 * Ver 1.1   Dec 14 95   Fixed random problems which occurred when the tape
 *                        shared an interface with another device.
 *                        (poll_for_dsc was a complete mess).
 *                       Removed some old (non-active) code which had
 *                        to do with supporting buffer cache originated
 *                        requests.
 *                       The block device interface can now be opened, so
 *                        that general ide driver features like the unmask
 *                        interrupts flag can be selected with an ioctl.
 *                        This is the only use of the block device interface.
 *                       New fast pipelined operation mode (currently only on
 *                        writes). When using the pipelined mode, the
 *                        throughput can potentially reach the maximum
 *                        tape supported throughput, regardless of the
 *                        user backup program. On my tape drive, it sometimes
 *                        boosted performance by a factor of 2. Pipelined
 *                        mode is enabled by default, but since it has a few
 *                        downfalls as well, you may want to disable it.
 *                        A short explanation of the pipelined operation mode
 *                        is available below.
 * Ver 1.2   Jan  1 96   Eliminated pipelined mode race condition.
 *                       Added pipeline read mode. As a result, restores
 *                        are now as fast as backups.
 *                       Optimized shared interface behavior. The new behavior
 *                        typically results in better IDE bus efficiency and
 *                        higher tape throughput.
 *                       Pre-calculation of the expected read/write request
 *                        service time, based on the tape's parameters. In
 *                        the pipelined operation mode, this allows us to
 *                        adjust our polling frequency to a much lower value,
 *                        and thus to dramatically reduce our load on Linux,
 *                        without any decrease in performance.
 *                       Implemented additional mtio.h operations.
 *                       The recommended user block size is returned by
 *                        the MTIOCGET ioctl.
 *                       Additional minor changes.
 * Ver 1.3   Feb  9 96   Fixed pipelined read mode bug which prevented the
 *                        use of some block sizes during a restore procedure.
 *                       The character device interface will now present a
 *                        continuous view of the media - any mix of block sizes
 *                        during a backup/restore procedure is supported. The
 *                        driver will buffer the requests internally and
 *                        convert them to the tape's recommended transfer
 *                        unit, making performance almost independent of the
 *                        chosen user block size.
 *                       Some improvements in error recovery.
 *                       By cooperating with ide-dma.c, bus mastering DMA can
 *                        now sometimes be used with IDE tape drives as well.
 *                        Bus mastering DMA has the potential to dramatically
 *                        reduce the CPU's overhead when accessing the device,
 *                        and can be enabled by using hdparm -d1 on the tape's
 *                        block device interface. For more info, read the
 *                        comments in ide-dma.c.
 * Ver 1.4   Mar 13 96   Fixed serialize support.
 * Ver 1.5   Apr 12 96   Fixed shared interface operation, broken in 1.3.85.
 *                       Fixed pipelined read mode inefficiency.
 *                       Fixed nasty null dereferencing bug.
 * Ver 1.6   Aug 16 96   Fixed FPU usage in the driver.
 *                       Fixed end of media bug.
 * Ver 1.7   Sep 10 96   Minor changes for the CONNER CTT8000-A model.
 * Ver 1.8   Sep 26 96   Attempt to find a better balance between good
 *                        interactive response and high system throughput.
 * Ver 1.9   Nov  5 96   Automatically cross encountered filemarks rather
 *                        than requiring an explicit FSF command.
 *                       Abort pending requests at end of media.
 *                       MTTELL was sometimes returning incorrect results.
 *                       Return the real block size in the MTIOCGET ioctl.
 *                       Some error recovery bug fixes.
 * Ver 1.10  Nov  5 96   Major reorganization.
 *                       Reduced CPU overhead a bit by eliminating internal
 *                        bounce buffers.
 *                       Added module support.
 *                       Added multiple tape drives support.
 *                       Added partition support.
 *                       Rewrote DSC handling.
 *                       Some portability fixes.
 *                       Removed ide-tape.h.
 *                       Additional minor changes.
 * Ver 1.11  Dec  2 96   Bug fix in previous DSC timeout handling.
 *                       Use ide_stall_queue() for DSC overlap.
 *                       Use the maximum speed rather than the current speed
 *                        to compute the request service time.
 * Ver 1.12  Dec  7 97   Fix random memory overwriting and/or last block data
 *                        corruption, which could occur if the total number
 *                        of bytes written to the tape was not an integral
 *                        number of tape blocks.
 *                       Add support for INTERRUPT DRQ devices.
 * Ver 1.13  Jan  2 98   Add "speed == 0" work-around for HP COLORADO 5GB
 * Ver 1.14  Dec 30 98   Partial fixes for the Sony/AIWA tape drives.
 *                       Replace cli()/sti() with hwgroup spinlocks.
 * Ver 1.15  Mar 25 99   Fix SMP race condition by replacing hwgroup
 *                        spinlock with private per-tape spinlock.
 * Ver 1.16  Sep  1 99   Add OnStream tape support.
 *                       Abort read pipeline on EOD.
 *                       Wait for the tape to become ready in case it returns
 *                        "in the process of becoming ready" on open().
 *                       Fix zero padding of the last written block in
 *                        case the tape block size is larger than PAGE_SIZE.
 *                       Decrease the default disconnection time to tn.
 * Ver 1.16e Oct  3 99   Minor fixes.
 * Ver 1.16e1 Oct 13 99  Patches by Arnold Niessen,
 *                          niessen@iae.nl / arnold.niessen@philips.com
 *                   GO-1)  Undefined code in idetape_read_position
 *                              according to Gadi's email
 *                   AJN-1) Minor fix asc == 11 should be asc == 0x11
 *                               in idetape_issue_packet_command (did effect
 *                               debugging output only)
 *                   AJN-2) Added more debugging output, and
 *                              added ide-tape: where missing. I would also
 *                              like to add tape->name where possible
 *                   AJN-3) Added different debug_level's
 *                              via /proc/ide/hdc/settings
 *                              "debug_level" determines amount of debugging output;
 *                              can be changed using /proc/ide/hdx/settings
 *                              0 : almost no debugging output
 *                              1 : 0+output errors only
 *                              2 : 1+output all sensekey/asc
 *                              3 : 2+follow all chrdev related procedures
 *                              4 : 3+follow all procedures
 *                              5 : 4+include pc_stack rq_stack info
 *                              6 : 5+USE_COUNT updates
 *                   AJN-4) Fixed timeout for retension in idetape_queue_pc_tail
 *                              from 5 to 10 minutes
 *                   AJN-5) Changed maximum number of blocks to skip when
 *                              reading tapes with multiple consecutive write
 *                              errors from 100 to 1000 in idetape_get_logical_blk
 *                   Proposed changes to code:
 *                   1) output "logical_blk_num" via /proc
 *                   2) output "current_operation" via /proc
 *                   3) Either solve or document the fact that `mt rewind' is
 *                      required after reading from /dev/nhtx to be
 *                      able to rmmod the idetape module;
 *                      Also, sometimes an application finishes but the
 *                      device remains `busy' for some time. Same cause ?
 *                   Proposed changes to release-notes:
 *                   4) write a simple `quickstart' section in the
 *                      release notes; I volunteer if you don't want to
 *                   5) include a pointer to video4linux in the doc
 *                      to stimulate video applications
 *                   6) release notes lines 331 and 362: explain what happens
 *                      if the application data rate is higher than 1100 KB/s;
 *                      similar approach to lower-than-500 kB/s ?
 *                   7) 6.6 Comparison; wouldn't it be better to allow different
 *                      strategies for read and write ?
 *                      Wouldn't it be better to control the tape buffer
 *                      contents instead of the bandwidth ?
 *                   8) line 536: replace will by would (if I understand
 *                      this section correctly, a hypothetical and unwanted situation
 *                       is being described)
 * Ver 1.16f Dec 15 99   Change place of the secondary OnStream header frames.
 * Ver 1.17  Nov 2000 / Jan 2001  Marcel Mol, marcel@mesa.nl
 *                      - Add idetape_onstream_mode_sense_tape_parameter_page
 *                        function to get tape capacity in frames: tape->capacity.
 *                      - Add support for DI-50 drives( or any DI- drive).
 *                      - 'workaround' for read error/blank block around block 3000.
 *                      - Implement Early warning for end of media for Onstream.
 *                      - Cosmetic code changes for readability.
 *                      - Idetape_position_tape should not use SKIP bit during
 *                        Onstream read recovery.
 *                      - Add capacity, logical_blk_num and first/last_frame_position
 *                        to /proc/ide/hd?/settings.
 *                      - Module use count was gone in the Linux 2.4 driver.
 * Ver 1.17a Apr 2001 Willem Riede osst@riede.org
 *                      - Get drive's actual block size from mode sense block descriptor
 *                      - Limit size of pipeline
 * Ver 1.17b Oct 2002   Alan Stern <stern@rowland.harvard.edu>
 *                      Changed IDETAPE_MIN_PIPELINE_STAGES to 1 and actually used
 *                       it in the code!
 *                      Actually removed aborted stages in idetape_abort_pipeline
 *                       instead of just changing the command code.
 *                      Made the transfer byte count for Request Sense equal to the
 *                       actual length of the data transfer.
 *                      Changed handling of partial data transfers: they do not
 *                       cause DMA errors.
 *                      Moved initiation of DMA transfers to the correct place.
 *                      Removed reference to unallocated memory.
 *                      Made __idetape_discard_read_pipeline return the number of
 *                       sectors skipped, not the number of stages.
 *                      Replaced errant kfree() calls with __idetape_kfree_stage().
 *                      Fixed off-by-one error in testing the pipeline length.
 *                      Fixed handling of filemarks in the read pipeline.
 *                      Small code optimization for MTBSF and MTBSFM ioctls.
 *                      Don't try to unlock the door during device close if is
 *                       already unlocked!
 *                      Cosmetic fixes to miscellaneous debugging output messages.
 *                      Set the minimum /proc/ide/hd?/settings values for "pipeline",
 *                       "pipeline_min", and "pipeline_max" to 1.
 */